Originally posted by MilkyJoe
Could you estimate a player's rating by going through some of their games? If so, how many games would it take to get a good idea?
chess is ultimately a game of who makes the fewest "blunders" -- the better your rating, the more subtle your typical blunders will be -- a blunder being a move that ultimately leads to a permanent loss of material -- or overlooking the chance to gain material -- and of course, moves that lead to being mated.
so - one could go through each game, see where material was lost, a pawn passed, or a mate happened, and then find out how it happened and how it could've been prevented --- and then judge how obvious or subtle the blunder was -- obviously, it would be harder to find the "missed opportunity" blunders.
there are probably computer programs that could do this and give a rather good estimate -- and I would guess you'd need at least 20-30 games to offset the occasional "DOH!!" moments that we all have.