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Staircase Statistics
Path: StatisticalAnalysis · Prev: CrossCutThenExtendTechnicalDiscussion · Next: EnclosingFromHoshiVersusShimari
Keywords: Shape, Tactics
DaveSigaty: I searched for the following pattern in the July 2002 GoGoD CD which has 17,000+ games. Note that it is a staircase with one empty row on all sides and no relation set to any side or corner.
WARNING!! TEMPORARY DISCLAIMER!!(Aftering putting up the analysis below I discovered what looks like a bug in the way that the latest version of Kombilo reports the winning ratios for Black and White on continuations. I wrote to Ulrich and am waiting to hear from him. Meanwhile, we have to suspend discussion of the results below until I can confirm whether the figures are correct or not. Dave 2003-01-06 Ulrich wrote back that it is a bug and that he will produce a fix, most likely this weekend. After that I will redo the stats. Dave 2003-01-07) 2003-01-15 The stats are revised. Unfortunately the tremendously clear message that I could so easily read into the incorrect stats is rather muddy with the correct ones. How typical! :-) Anyway contributors may need to reedit their comments and/or redraw their conclusions. Dave The search returned a little over 2400 matches in 2269 games from the middle of the 12th century through 2002. Five of the continuations occurred over 100 times. The results are shown below:
Black chose the cut 913 times, more than twice as often as any alternative. Black won 51.5% of the games and white won 46.1%.
The atari at 1 occurred 423 times, the next most frequent choice. Black won 51.5% of the time while White won 44.0%.
Thanks. :-) Dave: There are only 21 hits when the search is expanded to include two empty rows surrounding the staircase. Only two of these are the atari. Even I wouldn't claim that this tells us anything :-) Bill: Thanks for taking a look, Dave. :-) I agree, 21 examples is not enough to draw much of a conclusion.
The extension at 1 was played 418 times, slightly less than the atari above. Black won 54.5% of the games while White won 41.4%.
The solid connection occurred 359 times, the fourth most frequent choice. Black won only 49.6% of the games while White won 47.9%. This is the lowest winning percentage for Black among the major continuations.
The triple hane is the last of the significant continuations. It occurred 209 times. Black won 58.9% of the games while White won 38.0%. This is the highest winning percentage among the major lines.
Based on the above (admittedly superficial) analysis. Players faced with the staircase should consider all choices. The triple hane is the most aggressive choice and has produced the highest winning percentage but it is the rarest among the major lines. The solid connection has the lowest winning percentage by a slight margin and it is only fourth best among the major lines. Any of these continuations may be best for a given situation. All of them have produced a significant number of wins in top-level professional play. At the same time, however, there does not seem to be any support in these statistics for the claims on staircase and Hane-kaeshi follow up that playing solidly should be considered first or is "good style" in any general sense. Dieter: I find this extremely interesting. Could you extend your previous analysis of the cross-cut in the same way ?Thanks a lot Dave. GeorgMischler: I think this kind of statistic is very misleading, as it doesn't take into account the reasons why the position came into existence at all. Why does the solid connection give relatively bad results? Maybe because it is most often played when the first hane by b already was an overplay? And why was the overplay chosen? Maybe because b was already behind and had no alternative but to try an overly aggressive tactic as an emergency measure? The same goes for the cross cut, when seen from whites perspective. Would w chose to establish a staircase position while being ahead, even if the cross cut by b had good chances of working? (Of course I'm not saying that it isn't fun to look at those figures anyway... ;)
HolIgor: Naturally, Dieter's remark is true. Let us consider the staircase that usually appears as one of the variations with hoshi approached by keima kakari.
If black connects with 3 white has an exit to the center. Black has been cheated by white's staircase. It is only because this natural connection is bad that white provokes a fight with the staircase. Stefan: Is it? What if the pro is reluctant, but doesn't have a better move? And isn't it also conventional wisdom that pros look for sequences that give them an edge, but often play sequences that are even? Path: StatisticalAnalysis · Prev: CrossCutThenExtendTechnicalDiscussion · Next: EnclosingFromHoshiVersusShimari This is a copy of the living page "Staircase Statistics" at Sensei's Library. ![]() |