Geschrieben von:/Posted by: Albert Silver at 05 September 2004 20:18:46:
Als Antwort auf:/In reply to: Volker: How is the short-long time control doing? geschrieben von:/posted by: Dan Honeycutt at 04 September 2004 21:36:56:
A similar study has already been done and published by Ernst Heinz on diminishing returns. This pretty much answers the question as it deals with the curve at which point greater depth (hence longer time controls) yields less and less gains. You can find it by searching the CCC archives.
Albert
Hi Albert:
Is this the same data that Uri posted a link to further down in the thread?
Best
Dan H
No, it is a different one. Here is the link to the thread from the CCC archives:
http://chessprogramming.org/cccsearch/c ... ead=112634Albert
Thanks Albert. Interesting reading. If we start with:
(1) Long time control games tell you more than short time control games.
(2) More games tell you more than fewer games.
The ideal would be lots of games at long time control. But if you only have X time, is it better to play more games at shorter time or vice versa. Here begin heated debates, which I don't want to start. But the diminishing returns suggests that there is an optimum time control for giving the most information in a given amount of time. This, I believe, is what Volker Pittlik is working on with his short-long time control. Hopefully he will check in and give a progress report.
Dan H.
I don't think the question is really that hard to answer if you consider the results of the diminishing returns and the well-known branching factors.
Today's hardware, even my medium-speed Athlon 2400XP+ (2 GHz), can get engines to a pretty good depth quite quickly. I'm testing Pro Deo settings and running Nunn matches to see the results. I've chosen 30 minute games as my basic testing parameter. Slow enough to be fairly deep, but fast enough to yield a reasonable amount of games. Perhaps not hundreds at a time, but I can already get a feel after 30-40 games to how it is playing and what it is doing wrong. I naturally compensate some of the lack of numbers by using my personal judgement.
Let's suppose for argument's sake that a top program has a branching factor of roughly 2.5. Let's also suppose that an ideal slow time control would be 40/2h or roughly 5 hours of play. On average. If I cut that in 2.5, reducing my average depth by a ply, the game would be in 2 hours. If I reduce this by another ply it would be in about 48 minutes. The 30 min KO games are about that if not a bit longer. The average depth I see in the middle game (no pondering) for Pro Deo is 12-13 plies. Sometimes it's more, and sometimes less. So this is very roughly 2 plies less than what a 40/2h game would reach. Since the returns seem to start flattening at around 12 plies or more (IIRC), this is not far from optimal. Always IMHO.
Albert