|Table of contents|
To quickly find arguments for or against your position, just search for the below names. Of course, there are as many opinions as there are people in the discussion, so the characterization is only an oversimplification of the contributors' actual opinions.
(Regarding undo requests as the worst habit, generally refusing it, possibly except for teaching games:)
(Generally allowing undo for clickos or in other special cases:)
tderz: Taking back a move due to second thoughts is morally equal to have lost one game - especially in free games (because its forbidden in the other types!).
Who is asking an thinko-type of UNDO? I would say no strong player is requesting it. Not for the reasons of morally better even a tiny bit, rather being strong is the consequence of being responsible, being able to cope with mistakes, doing an effort, coming back. Even if a game is eventually lost after the most terrible, most stupid and most simple oversight, it would not come up in a players mind to ask for an UNDO. This oversight rather serves as a reminder to be attentive all the time, not to underestimate the opponent or the situation. Hence, eventually this setback makes the player stronger in the long run. A stronger attitude makes you stronger: its like in real life where whining about setbacks does not get you anywhere, only efforts to come out. tderz
This must be the worst habit, as it is close to a violation of the rules (Stones, once put on the board, can't move unless they are captured.)
I remember very distinctly a Japanese fellow, who was very well seen in the club, truly a nice person, always cheerful, showing this bad habit time and time again. One really needed to play fast, because if you wondered how to take best advantage of his mistake, he would take his move back, laughing to himself and tapping himself on the head for so much stupidity.
Andrew: When playing on the computer if you slip when clicking on the spot you want, asking to take back is fine if you say you slipped right away. Andrew describes here a misclick which the opponent realizes (depends on level and stage of game) without that the misclicker says anything. If I see such a move and think the opponent might have slipped with the mouse, not with his mind, I would ask and suggest myself misclick? and grant it if so wished (if not - it could also be a miaoshou). tderz
Iron Chef Sakai: Although I don't find it especially rude, it is a bad habit. You should think it out well enough not to have to take back a move. In an old Go instruction manual, it said that it is quite common to ask to take back a move and polite to allow it, but it is still a bad habit.
KSLO: I agree, a mis-click on the cpu should be returned, but it gets tricky. In a game I was playing, I needed an undo due to a mis-click. This was early on in the game, and an obvious slip, and my opponent granted the re-play. Later however, on the side of the board, White played into a modest little trap of mine and after a moment, asked for an undo. I paused, trying to think of a polite way of asking if this was a legit slip-up. He posted a "?", and when I asked, his first reply was, "I gave you one". He seemed to think the point was moot. After a bit of discussion, in which I explained my hesitation, he did finally say that it was a mis-click, but that he didn't want the move back anymore. He then stated that he would never allow me a take back move again. All very unpleasant. Now I'm more careful before I click.
hdouble: I have recently added "no undo, please" to my profile when playing online. I don't mind people taking back moves in a teaching game or casual in-person game, but online most of the undo requests I have received have been a little suspiscious (i.e. opponent made a bad move and noticed it 5-10 seconds later). I know that mistakes happen, but I would rather keep the game moving rather than have it get sidetracked by midgame debates over undos, even if I lose as a result. Besides, playing with the knowledge that no undos are possible encourages more thoughtful, careful play.
Neil: Go is not an arcade game rewarding precision clicking. If you won't grant an misclick undo that is requested immediately after a play, then you're no longer playing go, but rather some action arcade variant.
Besides, one can take comfort in the thought, "If he didn't know what he was doing when he made the original play, why should I think he knows what he is doing now?" ;-)
Scartol: Beware also when playing online that your opponent (mine was named "goeplayer0") doesn't hassle you for several minutes begging for a takeback, finally relenting only when you have 15 seconds left for 20 moves. If I ever meet him, I'm gonna break his legs.
Err... I beg your pardon?
Kidding! Hyperbole. Exaggeration for comedic effect and all that..
Justin: Requesting an undo online, unless it is for an obvious misclick and promptly requested, is inconsiderate of your opponent. One either has to allow it, reinforcing a bad habit, or deny it, thereby introducing tension and sometimes anger. Either way it's just uncomfortable. At the local club, requests for take-backs are virtually non-existent outside of teaching games, but it's not uncommon for someone to offer a take-back for an absent-minded blunder (e.g, not noticing atari). Seems like that's the way it should be: don't try to undo unless it's offered. And be generous in offering undos when appropriate.
Doug Ridgway: Online, I no longer request undos, even for obvious and unintentional misclicks. It's not possible for the opponent to tell, through the computer, to tell what's a "dropped stone" and what's a brain misfiring. (You can't tell from timing: the delay may come from dithering about whether or not to request the undo.) Strategically, I'd rather lose games from my carelessness in clicking than lose games from being distracted about undo negotiations. In my experience, a clicko is one bad move, but getting upset leads to about ten. When my opponent asks for an undo, I always grant it. (If I'm annoyed, I can say to myself, "We both know who won that one, shall we play another?" and then hit okay.) Having a blanket policy, and one that my opponents could never argue with, saves me time and aggravation, and lets me focus on the game.
JohnAspinall: My KGS profile says that I'll offer "Undos for typos, not for brainos", but I personally hold to the same standard as Doug Ridgway above, for myself. Besides, moral high ground aside, there's a much more guilty pleasure that awaits when you allow some undos:
Hu: I think the important thing about undos is that an undo for a clicko should be requested immediately. The longer the delay, the more the request will be mistaken for a request for an undo for a thinko.
When playing on a laptop, I alert my opponent to the fact at the beginning. It has occurred to me that some might interpret this as a strategy to prepare to ask for thinko undos, but I think it is fair, and I try to avoid thinko undos and ask for clicko undos immediately.
Warp: I once played in a local club friendly tournament against an opponent whose behaviour was simply incredible: At one point he played a move, pressed his clock button, thought about 10 seconds and then, without even asking took the stone back. I was amazed at this behaviour. He did not only failed to ask for taking back and simply just took it back, but had the audacity of trying to rethink his move on my time! When I asked him what the h*** he thinks he is doing, he just mumbled something about me not having made my move yet... He seemed to imply that as long as I don't make my move he could take his back.
Naturally I could have requested immediate disqualification, but since it was just a friendly tournament and there was no time problem I let this go as long as he put the stone where it was. He had to agree.
(This wasn't the only anecdote in that game: Later in the game he forgot pressing his clock button. I waited more than 5 minutes before he noticed. He had less than 1 minute left before byo-yomi. What did he do? Well, he tried to set the clock back while mumbling something that I surely wouldn't care if he did that... That was too much and I certainly didn't allow that.)
MarkD: Yes, there are some funny (and annoying) opponents out there Warp :)
I played an opponent who used his stones from the bowl and his prisoners to lay out some test moves during the game "Mhhh let me see, if I go here...you will go there....".
Just to annoy him I played a totally different move than the one he just tried (sort of a tenuki tesuji :-) ). His answer was "Hey! You are supposed to play there". After that, he took my move back. Just grabbed the stone and put it back in my bowl.
And no, he was not a child, but at least 40 years old.
Sebastian: This is certainly an outrageous story!
<rant> With regard to the normal undo request, however, I don't see why many players are so harsh. I, for one, can't get satisfaction by winning a game through a mistake that my opponent regrets right away - regardless if it's a clicko or a thinko. (At least not in a friendly game.) Expecting everyone to be that rigorous is a very nerdy and narrow-minded way of pulling up the ladder. It turns off many people (including many women) who otherwise could enjoy this rich and beautiful game as what it is: a game that also provides philosophical insights for life. Neither life nor Go are all about avoiding stupid mistakes. </rant>
SnotNose: My interest when playing go is to produce a game that is about as good as my opponent and I can muster. Therefore, sometimes when my opponent makes a bad move that I believe he should be able to recognize I sometimes ask if he is sure he wants to make that move. Sometimes I don't really ask it, but I just wait a bit and look puzzled. When my opponent groans or says "what a bad move I made" (or some such) I ask if he'd like to take it back.
This stems from my order of preference regarding outcomes of games:
1. I win but the game is very close and both players have played to the best of their ability.
2. I lose but the game is very close and both players have played to the best of their ability.
3. I win by resignation before another move below my opponent's level is made (by him/her).
4. I resign.
5. I win but by a lot and only after my opponent makes a lot of terrible moves below his/her level long after the game is over.
6. I lose but by a lot and only after I have made a lot of terrible moves long after the game is over.
The last of these doesn't happen as far as I can tell.
Sente5?: If my opponent whines and whines about how he didn't mean to move there blah blah blah, is it proper to
a) Kindly refuse to let them take their move back.
b) Let them take their move back but only if they promise to stop whining
c) Whack them on the head with the go board
zaintz14? I would say, depending on how heavy the board is whack him on the head because whining is a sick habit although, i see nothing wrong withtakingg back moves clicko or thinko unless your opponent has something against it.
tderz  If my/your (let's call this one B) playing style depends on fighting and good shape & calculation, than it is simply annoying if the player requesting UNDO (let us call him/her A) argues: "Yes, but it's such a simple, obvious mistake I committed. Without it I'd clearly won." If both are equally strong, then B will look weaker in the opening and early middle game, as long as complications and local fights have not yet started. B cannot ask to replay - say from move 20 onwards, just because this would give a better fuseki, because he wouldn't know which move to chose even after long thinking and fuseki errors are difficult to pin down. This equally starts another game as often can be heard in commentaries. Therefore it's grossly unfair to allow - equally decisive - error corrections in another stage of the game, where it's very easy to pin down the mistake. In non-ranked games I could allow as many UNDO-requests as wished as long as A agrees to the policy: 1 UNDO = 1 game (lost) (if you play Go, you want to win on the board, right? Could you play poker without money? Seeing the cards without paying?? ) . Otherwise these players come back later and tell you how well they won, how weak you were, want to play without handicap etc. They treat the game than as display for a bad habit solving tsume-Go problems (trying on the board with the hands fingering everywhere: "Ah, not correct? - Ok - let's see perhaps this works ..", this iterative). Of course, after some more time of thinking, also B might find a move for A which would solve fighting problems. Objectively, these moves exist many times and are usually undiscovered by both players ...
In post game discussions - which also can be won or lost - some players do not analyze with the intention for better moves (learning), rather they only want to find out how they could "have won" (if they lost). These approaches can be overlapping, but not necessarily.
If then another move is suggested with the lapidary "perhaps I should have tried this one" (without much analysis), then you can only agree, not without adding "and this would have been another game" (as it usually turns the approach: safe-risky, weak-strong group, sente-gote and/or gig-urgent etc.).
New category? SHIFTO from "to shift a stone".
You put down a stone on the still quite empty board (far away from the action) and then slide it (with your finger on it) to its end-position.
You never lift the finger off the stone, you never pressed the clock.
You think (loudly, saying something) while having the finger on the stone.
Imagist: I don't see the problem with this, as long as one doesn't linger with it on the board forever and don't remove your finger from it. In some cases this is the easiest way to get a stone where you want it without disrupting the surrounding position.
tderz Here a letter which I wrote for my opponent in a ranked online Blitz game, after he insulted me heavily after not granting his ~10 UNDO-requests on one move (it went on for several minutes):
Dear A-----, you are a player who I want avoid to play with,
because you were asking ~ 10x UNDO in a ratet fast game, did not accept your own mistakes and displayed weak attitude, rather got rude & insulting, think that you are so strong (in attitude?) and must tell it all the time.
I consider myself, especially in fast games, a weak 3dan. You completely ignore my ELO ranking ~ 2300 including many lost games due to timeouts. I have not seen you there, either on KGS or over the board. I use KGS as my training tool for becoming stronger at time management, hence facing my weakness.
In Go or whatever - strive to be a complete player. I never asked myself for an oversight-UNDO in 25 years !
Dear A------, Go games have some aspects of the sea, they are deep, wide and long. The waterline comes and ebbs away. It is usually not possible to say 'Well, I'm ahaed right now, so let's finish here and I have won' (Some stronger players in the past could pause some games forever with (socially) lower ranked players.)
The other player simply does not comply with this wish. Go is like a marathon, you must get over the finish line and this in time. In fast games the time is not my friend and - therefore(!) - I play those fast games as a training !
One move before you requested your UNDO, you were indeed ahead on the board.
Then, by inattentiveness, you ran into a simple and alluring trap, you - no doubt about it! - had avoided with more time available.
True misclicks must have the following characterizing 2 features:
(e.g. in the opening 5-3 approach to 4-4 will be understood as misclick and meant to have been at 6-3 low kakari). Believe me, in those cases most opponents would not have to ask me, rather I would suggest "misclick? - UNDO?". So, most true misclicks will be found in the vicinity of the meant place and can be evaluated easier in the early part of the game. Mouse anti-skid settings helps to avoid misclicks. Inspite that your UNDO request complied with above 2 criteria, there is a 3rd one necessary for granting it: UNDO is not meant for having second thoughts !
I did not allow your UNDO request, because it simply does not comply with the spirit of a ranked game. Consider UNDO suitable for true misclicks and teaching games. Our game did comprise neither of both. If you feel the necessity to ask for UNDO's for winning, perhaps free or teaching games are perhaps more suitable, if at all.
Also in our very 1st game on xx-yy-04 at 21:51:23 you had to ask for an UNDO in the first joseki (move 20) - otherwise you had lost the corner straight away ! Inspite you said so, it was not a misclick, because you played in the other corner. BTW, you then chose a wrong correction too (1st a15 , then b18 is better, you might have been confused by the ko aji ). I erred somewhat later with my move 47 leading to the loss of important stones. Did I UNDO? No, I devised a strategy which should use the stones properly! (and won)
I assure you that I did not ask to take back a move in similar oversight situations in 25 years ! It made me stronger and the attitude is friendlier vs. your playing partner. My philosophy is that both players constantly try their best to apply good stratagems (strategies/concepts) in Go and then either err in the chosen strategy or commit minor or graver errors in the tactical execution of it. The sum of all moves determines the strength !
In our 4th game of nn-mm-04 3:33:51 where you asked me ~ 10x UNDO for a single move in a ratet fast game. In the middle game I committed a serious mistake resulting in escape of your cutting stones in the top right corner, which I had caught in geta. Therewith my group was dead (30 points?) + your corner group was off-pressure + the center was not anymore W-dominated.
A-------, it did not occur to me at all, but would YOU have granted me an UNDO at that time? Remember, it fulfilled the same criteria as given above, mistake and obvious correction are clearly understood by both of us. The swing in game was very grave and was the cause that I was behind for all remaining moves. As you will have understood by now - I would not have asked for an UNDO even in a friendly game in a pub ! Stronger player's (I do not reckon me as one) attitude is to come up with the best moves available and create positions which might allow for a comeback. That one still has the possibility to do so depends on skill and all of the moves before - i.e. having played good shape and not aji-keshi . The more serious the former mistake was, the worse the situation is - the more risk one can and has to take afterwards.
In our 2nd and 3rd game I gave you 2 handicap stones and lost twice. Again your boasting attitude comes into play. While some jokes among friends are a funny way to socialize, I felt some unpleasant verbal aggressivenesss. Still, I agreed to play under your conditions.
A--------, I do not want to sound arrogant, yet here comes my advice for you:
__Mistakes, errors, oversights and wrong concepts - perseverance, confidence, concentration and time efficiency - all of this is part of playing strength.__
Only acknowledging one's own weaknesses is a start to surmount & becoming stronger! Never ask for UNDO again! Use anti-skid (on KGS). (Your opponent will grant you any true misclick) 
I always welcome any postgame review discussion on the technical points of games. However, to get rude & insulting, commenting on the alleged profession of my mother, my sexual preference, etc., my intelligence - and the only important and verifiable here - my level at Go displays a lack of good attitude and is often considered a sign of weakness.
Anon: tderz, on KGS, if you do not answer the undo dialog then it will "block" your opponent from requesting more undos.
tderz, Anon, you mean I could and should have played on the board, instead of clicking away his several UNDO?-pop-up windows . Really , they kept me busy! Just taking out the stones and end of discussion! Good point! Thank you. Reviewing his games I found out that at some times there occurs every 2nd day a rated, yet unfinished game in A's list. These will all be escaped games of this sort. Could one verify by whom they were escaped? It is not possible to download the SGF of these games. Will they become available sooner or later?
Anon: tderz, yes, you should have just played on. As far as I know there will only ever be _one_ undo dialog box open at a time (per game). So if you do not click Accept/Deny, then you can continue playing and put the undo dialog into the background.
As for the other part of your question, I do not know.
RobAnybody: I think that requesting an undo is a bad habit, not only because it's impolite/incorrect, but because the person making the mistake loses the wonderful chance to actually learn from it. Suffering damage from a mistake you stupidly made will certainly make the situation easier to remember next time and you will train yourself in the good habit of actually thinking before you move :)
I think that the didactical value of a game lost due to such an error is so great, that it is practically unfair against the misthinker to grant his undo request. I myself has recently suffered a lot of damage from thinkos and now I very rarely play without thinking.
(Sebastian:) This may be true for you, but people are different. Many people prefer to learn in different ways, and we should respect their choice. I don't know where the claim that one can only learn through mistakes comes from - maybe it's an urban legend created by self-proclaimed schoolmasters who know best what's good for others.
But even if learning through mistakes were the most efficient way for all of us, who says that all your opponents really want to learn? Maybe they just want to enjoy a game.
If your true motivation is helping others, then why not allow them the undo and offer them a review after the game? I suspect, however, that you, too, just want to enjoy a game. I don't think that a reasonable, polite undo request harms your enjoyment. Be honest: Could it be that you better enjoy a game if you win it due to your opponent's mistake than if you lose it due to your politeness? This, of course, is your decision, but please don't sell it as a superior position. I wish more people had different priorities (see above)!
tderz All those games & rule sets were offered by the opponent ("A"). He (not me) had chosen for ranked games not free ones. Hence, I do not grant UNDOs in his own chosen rule set!
RobAnybody: I realise my words sound a bit radical, here's an attempt to soothe them:
The role of mistakes during education is recognized and widely embraced by many didactical theorists. One of the main streams in didactics, constructivism, has this as one of their main points I think. Consider for example point 8 a) and d) in this resume: http://www.pedf.cuni.cz/kmdm/katedra/prednasky/09.htm You hit my words too hard - I never said that education is possible only through try/error, nor that all undo requests are harmful (to my enjoynment or to the opponent's learning)
It's true that I find learning through mistakes good, and it may not work for another, but still the important thing (from didactical point of view) in such a situation - as you say - is to review the game, discuss variations of the move.
Please, do not think that I care for winning or losing more than learning (I may even reach the radical - again - position of saying that I value learning go more than playing go, but that's too offtopic here). I understand that you're annoyed by my 'know-it-all' attitude here, but it's not fair to assign motives to my words...
I have myself played games (with and without) (wanting or giving) undo and I've decided to ask for undo no more. I also 'preach' this to my opponent, as I believe it is true for other people than me, but this has nothing to do with my decision whether to grant a request by my opponent. I also recognize the fact that if letting the other player undo will 'harm' me, then I've made a mistake anyway, and by my self-imposed rules above I have to accept it by allowing the undo. I know, because I have done this.
Does this variant sound better now?
 The bottom line is, we both have different ideals as to what constitutes a good go game. The word 'to preach' captures the situation well: We both have higher motives and we argued here as if our way was the only way to salvation. Many people here feel the way you do (see the related discussion on hard-heartedness). My request to all of you: Please don't preach to your opponent like a missionary, but offer your creed as a choice they can make, and respect that they may have different values.
tderz: Now I found out that players simply fall into either of two - mutually exclusive - categories: either one never does ask for an UNDO, or one seems addicted to it.
I dug into the archives of stored games and found many rated, yet unfinished games of the player(s) in question. In some cases it happened every 2nd day. These games are thus escaped before they could end in a proper way. Of course these guys & girls could have experienced the same by the opponent, if 2 seasoned UNDOers have met.
Just recently there was a game of an 8d against a 5d (rated) where the 5d was asking perhaps 9 UNDOs, of which 2 in direct succession. All where granted and after the 2nd or 3rd, it was clear that W knew that he was strong and vice versa that B was weak. Even with UNDOs some groups faltered. The UNDO-5d lost by 20+ points and was entitled to an 50 kyu-attitude diploma (because honest beginners are 30k).
Not having asked myself for an UNDO in a non-teaching game (rated, free ...) in 25 years, yet I have had an UNDO myself just recently:
in an atari sequence, a 7 dan played against me in a H4 game, I hallucinated that an atari was already given (it would come 1 move later) and connected there instead of blocking.
 To prove my point above, my opponent offered me a split second later the UNDO? and I took it!
I would not have asked for it myself, even if it had meant direct loss by cutting through my position (with the connected stones plain dead).
So I accepted the offered UNDO (without any bad feeling), because we both did not want to end an interesting game like this. And, mind you, it was not a misclick! It was not a thinko either, rather a hallucinato?^^, hence part of playing strength.
Hicham: Some people here seem to think that taking back a move is always bad. In my opinion, there are cases where an undo can make for a more enjoyable game. When playing a friendly game I recently missed an atari in late endgame( he would make a group live again and the game would be over), the move was made as a one point sente move, but I missed it. One could say: 'Tough luck!", but ... I didn't ask to take the move back, but my opponent offered it. We both felt that deciding a nice game after two hours of playing on such a silly mistake would take the fun out of the game.
I never ask for undo for a thinko, but when I misclick I do. This doesnt happen very often, so I am not a compulsive undo-er. But once again, I dont think one learns a lot from losing a game, 'cause your mouse is old or you slipped or something.
I am not saying that taking back a move is good, but i think there are cases where it is acceptable.(free games, when both players agree, and misclicks)
 (Sebastian:) I agree! I regard a game as a work of art, done by two people together in space and time. Obviously, if the time aspect prevails, as in tderz's letter above, there is no place for undo. But in a "nice" game (one in which I could establish rapport with my opponent), I sometimes ask for undo if it keeps us on the "main line" of the game in the sense of the intention of both players. (Luckily, KGS keeps the undo as a variation in the record, so I can learn from my mistake. Unfortunately, however, KGS does not allow two players to play out a variation. Not sure if I should make this a wish, though.) rubilia: This is supposed to be possible for demo games soon, as stated in KGSPlans (search for "so you can choose any two players"), so no need to add a wish unless you want to try variations in rated games. ;)
ilanpi: Sebastian, In the past I would have disagreed with you that go games are works of art. But, in the last little while I have been visiting various art galleries in my neighbourhood (Paris 6th) and have been impressed by the garbage that is being sold at most of these pretentious galleries. The most striking example was some artist who had the gall to build BMX bicycle frames and sell them as works of art for thousands of Euros, and I noticed that they weren't even finished correctly, he had forgotten to completely weld the rear dropouts. Pretty much like a typical blunder in a go game.
(Moved from Taking a friendly game too seriously:)
Talking about auto-atari's and taking back moves. How do you people (not addressing anybody here) feel about O Rissei, who in a very important game against Ryu Shikun for the Kisei title captured his stones after Ryu Shikun put himself in atari when filling up the dame's? Of course, this wasn't a friendly game at all. It was the most important title in Japan. But don't you agree that it's still bad sportmanship to try to win when filling up the dame's? Note: Ryu Shikun would have won without that mistake.
Well, I indeed disagree with the original statement. It does not make sense to me to distinguish between blunders, mistakes and bad moves. Where to draw the line? If instead of "auto-atari", you played a move which allowed opponent to capture in a ladder? Or a net, or something just a bit more complicated? Still take it back? I never ask to take anything back, and it is somewhat embarrassing when opponent asks me to do that, like you did in the game you described.
The game is destroyed in a sense, yes. But taking back destroys the beauty of the game for me just as well. Too bad, nothing to do but to start a new one. It doesn't necessarily have anything to do with taking the game seriously.
Josh Larson: In my view, taking back a move is synonymous with resignation . Playing from a takeback is for the purposes of 'what would have happened'. I have no problem allowing a take-back in this sense - to learn further from the position, see how the game would have played out etc.. I however make a policy of never asking to take back a move. I would rather admit my defeat and use my 'undeserved' loss as fuel for the re-match :)
Confused: At the low level I'm playing, I let my opponent undo whenever he wants to, but refuse to ask for undos myself. The first part is to force myself to look for moves I like even if the best reply is played and not to relie on my opponets errors. On the other hand, if I make errors I'd like to undo, it should tell me to pay more attention next time.
Migeru: I think in competitive games (including rated online games and club tournament games) undos are just out of place. For friendly games (free online games and club games) they are ok, but I generally hold myself to a higher standard than I hold my opponents, meaning that I am more likely to grant taking back a move than to request one.
In a friendly game between players of unequal skill, I have a feeling that the stronger player should never ask to take back a move, or accept an offer to do so. If the stronger player offers the weaker player to take back a move, the game might become a teaching game from that point on.
In friendly games between players of similar skill, the goal should be to create beautiful games. Taking back moves and/or discussing variations with the opponent should be ok. Among equal players there are no teaching games, but there is room for "cooperative self-study" games.
ilanpi: I had a couple of amusing Undo experiences recently. In one game, after I refused to grant Undo, my opponent wrote: "Now you allow me to escape." I thought he meant that his threatened group could escape into the centre. A while later, after I made a fairly good combination to capture some stones, he left never to return, and I finally understood what he meant... I guess that taught me a lesson, because in the next Undo scenario, my opponent wrote "looser", and this time, I didn't interpret it as meaning that my play was too tight for his taste. The last Undo/Escaper was some 6K guy on KGS who admitted it wasn't a misclick, but that he played quickly and hadn't seen my response. It seems even worse to insist on undo for an error when your opponent is giving you a handicap, where your win can only happen because of his error. My strict adherence to the no Undo principle was confirmed here, because he was threatening to escape, and my game was clearly won even if I let him Undo.
I believe that a player who writes or implies that he will escape if you don't let him Undo is being abusive, as he is trying to coerce his opponent into making a certain move. What's next, "play at R8 or I will escape"? I certainly believe that it is a more valid reason to be banned from a server than some of the reasons that have been quoted in the past.
(Sebastian:) Yes, this was abusive. I bet that these two were children. It's good if they learn that they can't always get what they want, not even by throwing a tantrum. It's a pity that escaping offers them an easy way out. I am one of the people who believe that escaping is still not discouraged well enough on KGS.
Bill: Gee, children were politer when I was growing up. Is this the result of TV? ;-)
ilanpi: Gee, if there was no TV when you were growing up, you must be olde (they were still spelling it that way back then?).
Bill: I remember when, of an evening, we used to sit and watch ye radio.
Bill: Hmmm. Go players were politer when I was learning go, too. <sigh>
About banning: Yes, people have been banned for lesser reasons, such as swearing. But banning is not just about avoiding annoying experiences for you and me. Let me look at it this way: I believe that playing on KGS is a character shaping experience for children. Next time when my opponent writes "My mother says I have to stop now" I will offer to chat with their mother and say this. I only can say this if I am sure that KGS provides an environment that is good for her child. Although I personally don't have a problem with swearing, it is a concern for many parents. So it is necessary to ban people who contribute to the impression that it is accepted. OTOH, people who threaten to escape do not come across as "cool". Sooner or later they will realize this and stop it. I've seen it happen! There is even a chance that each time they do it they teach their opponent what it is like to be on the receiving end of a tantrum. No parent would be concerned about that. I don't think they need to be banned.
ilanpi: Pretty funny, Sebastian. Actually, there are many more children on Yahoo than on KGS, and it makes for more frustration, but more amusement too. Check out my Yahoo page http://cf.geocities.com/ilanpi/yahoo.html
As for the problem of Undo and escaping on KGS, I believe that the perfect solution would be to allow Tournament Mode as a regular option. This way, you would be assured that there would be no undo or escaping before starting the game.
There is already a measure in place to deal with this issue as you are most probably aware. I don't think you have a proper perspective on this issue. If your opponent escapes you win, enjoy the win, don't miss the rating points because life is too short.
ilanpi: Your life may be too short. I find mine quite long and mostly boring (why else would I waste so much time playing go?).
Zinger: Mainly, I think undo just makes you weaker, or at least inhibits you getting stronger. Therefore, I have never done it - not once ever, for any reason, in any kind of game, even when my opponent graciously offers. As to my opponents, I allow it in casual games. I figure, this way better moves are played against me, which helps me get stronger. However, I don't allow it in tournament games or rated online games. Clicko you say? Well, you should be more careful, or for heaven's sake turn on the anti-mouse slip feature. Or just play free games.
Malweth: Regarding differentiating between "Clickos" and "Thinkos" - I believe that it's very easy to tell the difference in 99% of the cases. First of all, almost all misclicks that I've seen have been in a completely different part of the board (tenuki) and often on the first or second line. The reason for this may be that players are used to keeping their hands off the stones (er... the mouse, anyway) and that when it's time to play, the hand goes immediately to the mouse, inadvertantly clicks (either button will work -- right mouse button misclicks are also common) and since the mouse has been sitting there for a while, a stone appears (even with anti-slip on). These get an immediate wait for about 15-30 seconds (I don't talk during a game, unless I'm teaching and the student wants active commentary).
"Clickos" versus "Thinkos" are much harder to determine in L+D situations where the click occurs in the local situation. This is typically a judgement call and often time based (if my opponent took too little time - and isn't short on time - in a hard to think area, it's probably a misclick).
In any case, I offer undo for obvious (to me) misclicks only. Personally, I think no judgement is needed on the part of my opponent. Declining or Accepting the undo is my prerogative - I don't need to have a reason either way (my friendliness level with the opponent and the game-type are also factors).
P7A77: Not that this discussion needs any more input, but that never stopped me before. :)
When I was still a new player at club, I asked for an undo after a bad play with a much higher ranked player. He allowed it and didn't shame me, but I realized that I was being rude and felt sheepish. Up until then I had been playing online, and this in-person interaction cured me of asking for them from then on out. If I make a bad move, I make a bad move, and I need to learn how to live with it. At my mid-kyu level, there will be plenty of mistakes on both sides. I only request undos if it's a misclick.
My policy on allowing them varies. If it's a game with a weaker player, I'll allow it. If it's an even player and I feel good about my play, I'll allow it. If it's a misclick, I'll allow it. If it's late in a close game or in the middle of a vicious battle, I won't allow it. I have never had a stronger player ask for one.
Recently at club, the same person who granted me that undo many moons ago fell for a trap in late mid-game that allowed me a throw-in and a connect-and die, one that signifiacntly altered the results of the game. He resigned, then went back a few moves to try again, also incorrectly. Changed again and we achieved a more balanced result, which allowed for interesting yose. When some other players came over at this point and commented on who was winning, my opponent mentioned that he had already lost twice. Turns out he lost that third time, too. His behavior, to me, is very respectable.
The other night I was playing an even game online and made countless errors early on while trying to save a group. I kept increasing his wall and my losses. I finally moved on and was able to use threats to save this group as a means to make greater profit elsewhere. Being a weak player still, I made more mistakes, which allowed him to make it a dead heat of a game. He had sente and played a yose move. I responded. He asked for an undo. When I asked him if it was a misclick, he hesitated, then said that he realized it didn't work (I guess he was planning a trap?). Since I had been sweating out the game and hadn't asked for any undos, I told him we all make mistakes and refused it. He didn't push the issue or complain, but the undo request seemed rude, especially since I had responded to his move.
Obviously there are no absolutes. I have some people I spar with regularly, and I would not be averse to an undo in any of those games (at the same time, I can't recall the last time one was requested). And of course really dumb mistakes that would ruin the balance are best taken back. But even still, if someone offers such a thing to me and I accept, I don't feel like it was truly the game I played. I'm a little twitchier about it online than I am in person, especially in rated games. In person I can tell myself that I won the first game and we're playing out a second. Online, it's partly because I want my rating to go up, darnit, but also because if I then lose the game, it's not accurate. Do that enough times and my true strength will be higher than my represented strength, which leads to sandbagging. In the end it's a minor issue, so it's probably more that I want to have a good game history than any other rationalization I may dream up.
 as in "Cincinnati Kid", where The Kid (Steve McQueen?) plays five-card stud against Lancey Howard (Edward G. Robinson) who tells someone else "teaching costs extra" (who wanted to see the cards).
chrise There shouldn't be an undo option. Simple as. If you misclick, tough. I've done it myself, didn't ask for it back. Once the stone is down, it's down!
I once opened a game on KGS but the game window didn't appear immediately, so i clicked on the screen only to see the game appear with my opening move on the 1-2 point! Of course my opponent was from the hawk brigade and would not allow an undo. There it sat for the entire game. Had i won i would have felt very smug about it... I lost, so i'm sure my opponent feels good. - Binky
Alex: On most servers, games with less than 4 moves don't count towards ratings or even get saved in your games list, so if you clicko on your first move and your opponent wants to be a jerk, just resign and play someone else. Alternately, if you're feeling childish, let your clock run down to 0 and lose on time. :-P
GammaTau?: I feel that too often people disapproving of undos are represented as some kind of hard-liners or "hawks" as this page describes them. My stand on the issue is entirely different. I feel that all go players make mistakes and that is an essential part of all games with two human players. Occasionally we all misread sequences, rush our moves too fast and generally make all kinds of blunders. Basically I feel that those who see asking undos as a generally acceptable practise are the ones who represent a very hard stance on playing. With many mistakes erased from the game records, they try to erase the human side from the game and replace a small part of it with a superhuman time-traveller. It is a fact that we make mistakes and I feel that accepting undo would be partially denying this.
As everyone who regularly plays on KGS, I have had many experiences of undo requests. Sometimes they have been obvious misclicks, sometimes rather obvious thinkos (like self-atari) but there are also some very calculating undo requests. At some point I had a habit of accepting all undo requests because I didn't want to get in any verbal fights. In one game we had reached yose and the byo-yomi had set in. My opponent played a gote move worth of three points. Just as I was about to answer, he requested undo. I accepted it and he replaced his three point gote with a five point gote on another side of the board. Now, certainly, playing a three point gote is a mistake when a five point gote is available. However, it's not the kind of a mistake that is usually given as an example of an undo request. Yet I have seen many cases like this. When it is considered ok to ask for an undo, people ask undo in order to play better, in order to win the game. They don't ask for forgiveness, they use all accepted means available to get a win. That is again a rather hard stand on playing go and has very little to do with friendly attitude.
As a practical issue, I think that having undo buttons available in ranked KGS games encourages their use. Such a button should not exist in ranked games. Because it exists anyway, I tend to accept undo requests and accept the fact that we're no longer playing a real game, just speculating what might have happened if the real game had went otherwise. If someone asks for an undo, they want to stop playing a real game and there's very little I can do. If I make a stupid blunder or a misclick, I might get upset but on the other hand, I recognize that it was entirely a failure on my own. My intuition and play is still far from perfect and I'm fine with that. Anyway, as long as the button is available, I don't think I can play any serious games on KGS. I can play for pure fun, of course, but when you're in the right mood, playing seriously creates certain enjoyment that pure friendly games just can't reach.
As for misclicks, playing a misclick creates unwanted hassle and confusion. Respect your opponent, concentrate on the game and don't misclick. If you misclick anyway, accept that you are the one at fault, not your opponent. Good mice are not expensive and please, when you play online, use a good mouse. Don't burden your opponents by bad hardware choices.
Comment by motty:
There is a simple solution. Never ask for an undo and never give one. Most of the difference in strength between two players is in the frequency and severity of their errors. If someone is playing for fun then losing through a sloppy move should not be a problem. If they are playing to improve then the harshness of suffering through their mistakes is the best way to learn to play more accurately. If someone just wants to win no matter what, and is prepared to use undo to play only a slightly better move, or to unsettle the opponent, or worst of all, refuses an undo after being allowed one himself, well who cares whether someone like that gets upset or not. It is their problem. As for go-servers, there is a simple solution there ... if either player has "no undo" in their profile then the undo buttons should disappear from the interface. If there is no way to take a move back then there can be no unpleasantness or moral dilemma for the players.
Bill: For online play, there is another simple solution. When a player makes a play, it appears on their board, but is not transmitted for one second unless he takes another action to send it (such as a carriage return). During that time the player can undo the play by clicking again on the same point. That should eliminate almost all clickos, and avoid requests to the opponent for an undo. For speedier play the player could eliminate or shorten his own delay in sending plays.
jwaytogo: My approach to the issue of takebacks is rather didactic. Personally, I consider myself a hawk. I was raised in the game to believe that asking for an undo is sacrilege in terms of etiquette and professionalism. Hence, I think that one should never ask to take back a move under any circumstances. Even for clickos, I believe it is the players responsibility to make sure the aim of the mouse is sure and true. In real life, if you drop a stone and it lands on the board, so be it. A steady hand is a sign of a steady mind, and a fumbling hand...(well, its like asking not to be killed in a first person shooter just because my hand slipped before I fired off my last sniper round, or taking back my chips in the pot just because the card I wanted did not come up). On the other hand, I think it is probably ok to grant undos, if you judge your opponent to have slipped, and feel that the error would have ruined a perfectly good game. However, the right to an undo is the prerogative of the other party, not the person who committed the foul. It should also be noted, as mentioned many times before in the discussion above, that granting an undo is not necessarily doing your opponent any favours. You will have to judge what is more instructive for yourself and for your opponent. As the stronger player, granting the undo might prove more instructive in an interesting game. On the other hand, not granting the undo might just be as instructive a lesson on the importance of thinking things through thoroughly or just being steady in general. As the weaker player, granting the undo might be something you do out of respect for the stronger player who might be your teacher or friend, or because you feel there is more you can learn out of the game and can pitch it to your opponent as such. Not granting the undo is just as valid so as not to insult your opponent by insinuating his/her need for such petty things.
axd: (rather than soup up read-only discussion space, I'd like to poke here if there is any mentioning on SL of a related aspect:) suggesting undo?, because for example you know that your opponent is far better than the blunder (s)he made, because you don't want to win such a victory, have the opponent go banging his/her head against some wall, etc... IMO this doesn't apply for tournament games - unless sportsmanship is one's highest principle. (so this is not a case of asking an undo, but proposing one for a move of the opponent.)
someone once pointed out that this was showing lack of respect (I guess meaning "pointing out the stupidity of the opponent"). Not to me, I see this far deeper: letting a game go down the drain because of some really stupid move is like tennis, where you would overrule (if that exists) a line judge wrongly calling the opponent's ball "out" - even if this would cost you the point. but notice the common denominator here: "sportsmanship".
Tamsin: There's also the situation where a player makes a blundery-looking or misclickish move early on, but which could simply be a a dubious experiment. What do you do? I read once that in the early days of IGS in matches between the strongest players that one would wait for a few seconds or say "?". Is it reasonable to suggest an undo? Or even to say "I've never seen that idea before!"?
axd: Discussing with a colleague go player, he suggests that there is a more fundamental issue (than sportsmanship): a stone, once played, is never removed; which sends such discussions to the academic level. And another issue: what if you suggested an undo because you thought that the opponent was aware of the problem but lost sight of it? If in reality (s)he never saw the problem, the undo suggestion might come as a surprise. In that case, the correct next step (sportsmanshipwise) would be to admit the oversight and not accept the undo proposal...