Author: Komputer Korner
Date: 21:18:43 10/22/98
Go up one level in this thread
On October 23, 1998 at 00:03:51, blass uri wrote: > >On October 22, 1998 at 22:43:35, Komputer Korner wrote: > >>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. > >I agree that my calculation was wrong >The probability for a draw should be 33% and not 23% if >the probability for white is 40% and for black is 27% >so the ratio should be 1.53/1.14 > >It is higher than the present system so if we want to change the system it is >better to give black more for a draw then white. > >Uri > > >> >>-- >>Komputer Korner I won't argue against that( giving black more than white for a draw) because it would make mathematical sense, but you would be talking fractions here which would get too messy on wall charts and would be resisted by the community at large. So I guess the present system will stay. -- Komputer Korner
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