Rules: same as normal Go, except:
- Players may not pass on their first move.
- The player with the lowest score wins.
- Always use area scoring.
- No suicide.
Ranks in this game could be located in the same scale as they are for regular go; 9 dan - 40 kyu would all be very bad, 50-60 kyu would be random play, also quite bad, and I suspect that 70-90 kyu would be good.
Komi would be 0, or maybe given to black as compensation for going first.
You probably wouldn't want to play this on a big board, and you probably want to use super ko.
Experts at this game will force their opponent into making a large live group (i.e. another play would be suicide). e.g.:
Black wins, 3 to 5. (Black passes; White does too, but only because there's no legal moves.) (No, I don't know how we got here.)
(later) No, white wins: since White's stones are technically dead, Black owns the whole board.
So your goal is to get the other player in a situation where they don't have any legal moves, and they have more stones on the board than you do. Whether that is possible, I don't know. I've never tried playing this...
Sample 1x3 game:
White will then pass and black won't be able to make a play.
LukeNine45 (later): I strongly suspect that with perfect play this game will always be a tie, hence komi should be zero. Also, now that I've thought about it a bit, I think it might be rather easy to play perfectly, and so there would only be a few ranks between random play and perfect (bad) play.
Phelan: Heh, interesting variation. :) I just think you forgot about the ability to resign a game. I'm guessing it shouldn't be allowed.
MrTenuki: Not necessarily-- in this game, continuing while dozens of points ahead would be considered a bad habit. (In other words, resigning means admitting that there is no way to end up with a lower score than the opponent.)
Phelan: Hmm, didn't think of it that way. I was thinking of resign as something of a quick draw option: first one to resign wins. :p
fractic: This can't really work. I mean how are you going to stop Black and White from both playing one move (forced) and then passing?
blubb: Indeed. I believe, too, a perfect opponent-neutral player of this game would pass every move possible.
You could change the rules such that passing is never allowed, though (or equivalently, is treated as resigning). That might lead to the "odd" game you actually imagined, instead of trivial two move games that end up as seki. As opposed to normal no pass go, the winner then would be the player who runs out of legal moves first.
kb: Actually, when I was in Hong Kong teaching Go sometimes other teachers and their students would play a game like this and said it had been around for a long time. You cannot pass and I believe the rule is the first person to capture a stone loses. I'm not sure of that though. I just remember two people playing a long time and filling up their own territory until one of them had to capture all of the other player's stones, then they quit.
LukeNine45: Yeah, we could say "no passing," but I'm trying to make it as close to "backwards" real go as possible.
I think it can be salvaged, maybe. Here's a commented game to show what I was thinking originally:
Black: "I've clearly won, because is dead."
White: "No, is dead. I've won."
Black: "I guess we'll have to play it out to see whose stone is really dead."
blubb: Most area-scoring rulesets of normal Go allow an agreement about group statuses as a shortcut, skipping the rest of the game that would merely consist of capturing groups which both sides know are capturable with no effect on the score. If the players disagree, play continues as usual, that is, with any legal move. The players may therefore keep on passing, so no stones are removed. In that case, the board is scored "as is". Some details still depend on the ruleset, of course, but as far as I know, that's the general idea. The "as is" score serves as fallback reference, so a player has to prove s/he can really expel all opponent's stones from points s/he claims to own. If this fails, those stones count as alive.
LukeNine45: Agreed. So below, Black is "proving" that his stone is really dead, by turning it into a one-eyed group. Ouch, this hurts my brain.
blubb: In order to prove that you are able to capture a group of the opponent, you can simply capture it. However, as long as passes are allowed and your opponent in turn does not want to capture a group of yourself, you usually cannot force him or her to prove that s/he is actually able to do so.
LukeNine45: Yeah, it's not looking like this will actually work. Bummer.
At this point there's a couple options.
1. White passes:
Black: "You can see my stones have only one eye and are thus dead, so the whole board should be counted as your territory.
So passing doesn't work as a strategy.
blubb: I see 9 moku here, all of which counting for Black. White has none.
By this logic in my diagram at the top white should claim that his stones are dead and that black has won (so I changed it).
2. (the other option, which is what I hope will happen) White and black play to try and take the smallest amount of territory.