Author: Adam Oellermann
Date: 01:27:02 08/01/01
Go up one level in this thread
On July 31, 2001 at 19:18:36, Roy Eassa wrote: >On July 31, 2001 at 15:26:08, Ed Panek wrote: > >>On July 31, 2001 at 15:24:48, Roy Eassa wrote: >> >>>On July 31, 2001 at 15:21:17, Ed Panek wrote: >>> >>>>Lets say I have a move generator that selects a random move every time it is its >>>>turn. What are the odds against it drawing/winning a game? Is it less likely >>>>than winning a game of Keno with all the correct numbers picked? >>>> >>> >>>Is the opponent Kramnik or Deeper Blue? Or a human rated 400? Or another such >>>"random" program? I think this matters. >> >>Lets try a random opponent first...and then Kramnik >> >>Ed > > >Obviously, the chance of beating another random-playing program is 50% (not >counting draws). > >The chance of beating Kramnik or another top-notch grandmaster is so small as to >be essentially zero. Perhaps one in (ten to the power of 40). > >What might be most interesting is estimating the chance of beating an extremely >weak human player -- I don't know how low ratings go, but say USCF 400. (I have >a friend with a 4-year-old daughter who knows the rules of chess but not much >more.) Then the question becomes: how much better (or worse?!) than random are >that player's moves? When I got started with my chess program, I wanted to test my move generation and so I implemented exactly that; a program which would play chess by randomly picking a move. It played a few games against my wife, who is in the category of "knows the moves but hardly ever plays"; it never survived a middle game. I would suspect that even a four-year-old who knows that "it's good to eat the pieces" would win well over 99% of games, although obviously I don't have much in the way of stats. Some quick calculations in order to make this seem scientific... - Branching factor is (say) 20 for the first 20 ply. I know, it may be more. - Nothing reduces branching factor, because there is no eval/search - Assume that to have a decent position in the middlegame against a novice, you need to pick one of the top 4 moves in a perfectly-ordered move list. - after 20 ply, the odds of having a decent position are 0.2^10 (you're only playing alternate moves), which means the odds are 0.0000001024; or you'll get one decent middlegame in about 10,000,000. After that it gets worse; there are fewer good moves and potentially much more branching in the middlegame. I therefore can state with some confidence that the random-mover will never beat the 4-year-old. Implication: 4-year old is at least 750 elo points ahead of the random mover; which means the random-mover is probably negative Elo (if such a thing is possible). Puts me in mind of a big heap of monkeys, a big heap of typewriters, and Shakespeare. Cheers Adam
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.