Author: Jeremiah Penery

Date: 13:53:04 10/16/99

Go up one level in this thread

On October 16, 1999 at 11:55:16, Ratko V Tomic wrote: >> Even after seeing your equations, I'm still not sure how you can >> determine the pondering percentage by the winning percentage. > >If you know the rating difference you can compute total/effective thinking time >difference or time ratio (using D=C*(R-1), using value C=100 rating points gain >for doubling the thinking time). Once you have full thinking times ratio, and >you know the time controls each _nominally_ got, you will notice that the >effective thinking time ratio (as obtained from rating difference) is greater >than the nominal time controls ratio, e.g. in the 1st match both had equal >nominal times, but the time ratio from performance difference was 1.78, i.e. the >pondering Rebel had more actual/effective time. Hence you can compute how much >extra time the pondering version got to reach the times ratio expected from the >performance ratings difference. That extra time can only come from the pondering > time gain, and that's how you get G, the gain hit rate. (Obviously, in a fairly >small sample as this you have a significant statistical error marging, so take >the numbers 80% with a grain of salt.) > > >>If pondering Rebel had win 100% of the games, would you say it pondered >>with 100% accuracy? > >No. That could be only due to a statistical fluctuation in a 100 (or any finite >number) game match. For example, if instead of different time controls you used >depth D and D+1 versions, the D+1 will guess correctly the move of D version in >every single move, 100% guess rate. I don't think this is true. I think the D+1 will ponder different moves more than 20% of the time, or maybe more. Even D vs. D would have about 20% pondering difference. This is because in D vs. D, say one searches to 8 ply, then begins to ponder. The next one searches to 8 ply, but it's already one ply ahead of the other, so effectively it was like a 9-ply search from the first one. Since at any given ply depth, the probability of an engine changing its best move is around 20% (see "DarkThought goes deep" and "Crafty goes Deep" from JICCA. Unfortunately, I don't have real references to these, but I believe they're on DarkThought's webpage.), there will be a 20% pondering difference. With D vs. D+1 this will be even more. > Yet it will lose 20-30 percent of games. >Guessing what the opponent will play doesn't mean it will find a correct answer >to that move. But obviously it does most of the time. >>(And were you not the one saying that a shallower >>search can produce ultimately better moves in >>many cases? In these cases, a correct pondering would _worsen_ the result. :) >> > >It's not something I made up. Yes, I see that, but if this happened as often as you seem to say, the ~80% pondering accuracy of Rebel vs. Rebel wouldn't have such a large affect on the match outcome.

- Re: PB-ON vs PB-OFF (final results)
**Ratko V Tomic***16:24:58 10/16/99*- Re: PB-ON vs PB-OFF (final results)
**Jeremiah Penery***17:25:44 10/16/99*

- Re: PB-ON vs PB-OFF (final results)

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