Following Mogo, Pebbles uses the "3-in-a-row" modification that automatically plays in the center of 3-point eyeshapes.
Mogo's rule guarantees that an opponent will not be able to convert a 3-point eyespace into two eyes. The downside of Mogo's rule is that it wastes a *lot* of moves when it generates such plays where the opponent strings have other eyes. Following Fuego, Pebbles has the "upgrade self atari" rule that moves attacker plays to the center of 3-point eyes. Fuego's "clump correction" rule upgrades the defender's plays. Fuego's rules triples the chance of making a correct play when a 3-point eyespace exists, but does not guarantee that any play will be made. The rules do guarantee that the best move will be made *within* a 3-point eyespace. This allows RAVE to accelerate discovery of life-giving shape. The only downside that I have noticed is that straight-four eyespaces are more likely to die in the playouts, because attacker moves are upgraded to center points, and pattern replies are not guaranteed to be made on the vital point. When Mogo's rule was first implemented, it made a huge increase in strength. But when Fuego's rules went in, then Mogo's rule started being less important, and now it has even become a disadvantage. My impression is that Fuego's rules covers a lot of situations, and the upgraded move is almost always an improvement. Perhaps Mogo's rule would be beneficial if the number of wasted moves could be cut down. I have not looked into that. I have implemented a rule that plays on the vital point of nakade shapes after captures. That rule has never made much effect on playing strength, but it looks great in particular cases. It should work out to be a low-cost positive. Note that all Pebbles testing is on 9x9. I expect situational rules to be relatively more important on larger boards. _______________________________________________ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
