Author: Komputer Korner
Date: 19:43:35 10/22/98
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On October 22, 1998 at 03:49:12, blass uri wrote: > >On October 21, 1998 at 23:57:40, Komputer Korner wrote: > >>Presently there is a huge argument about alternative point scoring systems on >>the RGCC. The one that generated the hotly debated proposal was 3 points for a >>win and 1 point for a draw. I mistakenly assumed that the proposal was for 1/2 >>point for a draw. My original post on RGCC is copied below. However even if you >>substitute 1 point for the 1/2 point in the equations below, the advantage ratio >>of white will still be larger than under the present scoring system. For proff >>of that I repeat the equations below with the 1 point for a draw. >>White expects (3*0.31) + 1*0.50)= 1.43 points. Black expects (3*0.19) + >>(1*0.50)= 1.07 points. The white to black ratio becomes 1.336448 which is >>between the new ratio below (which mistakenly assumed 1/2 point for a draw) and >>the old present rules ratio. > >The probabilties are not right >I checked the ssdf games and I found something near 30% draws. >I do not know about 50% draws in low levels and you said that the proposal was >not about GM games > > >> >> >>"It will only increase the advantage of playing white which is already >>large enough. White players enjoy a 56-44% advantage. Assuming 50% of >>games are draws (the advantage of playing white will be even more >>under your new system if you assume less draws), this means that the >>spread is 50% draws, 31% white wins and 19% black wins. If you give 3 >>points for a win and 0.5 points for a draw , > > >> white's expected score >>will be now (3*0.31) + (0.5*0.50) = 1.18 points every game. >>Black players will now expect (3*0.19) + (0.5*.50) = 0.82 points every game. > >I do not agree because the players will play differently and the probabilities >can change to 40% for white and 27% for black > >In this case white expected score: >3*0.40+1*0.23=1.43 >black expected score >3*0.27+1*0.23=1.04 > >Uri It doesn't matter what % draws there are as long as white's overall score is greater than 50% and this is true for any ELOs above 1800. As long as white's overall score is greater than 50% the equations hold for any draw % you want to plug in. Your last comment still backs up the conclusion that white's expected score is higher than black's. Therefore if one player gets a greater number of whites in a swiss which is already the case, then any proposal to award wins by a bonus over the present system of awarding 1 point for a win will skew the white winning ratio higher. Indeed in your last calculations the figures are wrong. They don't add up to 100%. The last term of each equation has to be 0.50 to represent the draw. Even so you still show 1.43/1.04 which is a higher ratio than the present system. -- Komputer Korner
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