My conclusion was that the winning percentage is more than just an
estimate of how likely the player is to win. It is in fact a crude
estimator of the final score.
Going back to your original comment, when choosing between move A that
leads to a 0.5pt win, and move B that leads to a 100pt win, you should
be seeing move B has a higher winning percentage.
Darren
Good point. Wins will occur in clusters, so win-rate and score go hand in
hand.
MC algorithms seem to be treacherous ground when it comes to anticipating
consequences.
Here's another shot:
MC bots play handicap games poorly.
When they take w they go into maniac mode because they can't find any wins.
When they take b they dither around until the game gets close.
What is entirely missing are the concepts of catching up or of preserving a
lead.
So my suggestion would be to pretend that there is a komi that almost
compensates the handicap.
A numerical example: a 4 stone handicap is worth about 45 points.
Start with a "virtual komi" of about 35 points, and decrease that value to 0
during the course of the game.
This works in both directions. If the bot has w he will be pessimistic, but
not suicidal.
If he has b he will be optimistic, but not so lazy.
The rate of "giving rope" should depend on the number of moves played and on
the winning percentage.
If the winning percentage drops early, reduce the virtual komi more sharply.
One advantage of this approach would be that it wouldn't tinker with even
game stategies.
A more elaborate scheme would be to make several preliminary searches at
different komi levels.
The goal would not be to find the best move. The search would only try to
find the win rate for the komi.
Depending on how far the game progressed, giving a virtual komi will be
worth some win rate reduction.
(Or taking a virtual komi will increase the winrate, making the bot play
less maniacal than playing a string of kothreats in an unfavorable position.
After a decision on the komi is reached, a search is done for this komi to
find the move to be played.
Towards the end of the game the virtual komi must allways be 0.
This strategy might even be useful for even games, when the winrate strongly
favors one side before the late endgame.
That would revert to the handicap game situation.(Except that a disparity
of strength is not presumed)
Stefan
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