Side to Move Bonus---does it help?

[mjlef]

Has anyone done testing on the Side to Move bonus, and if so, how much does it help (if anything)? It would seem simple enough to test some public source programs with and without the bonus to see if it helps. Mayve Bob can use his amazing cluster to see the effect...it might be small and require a lot of games.

[Dann Corbit]

Has anyone done testing on the Side to Move bonus, and if so, how much does it help (if anything)? It would seem simple enough to test some public source programs with and without the bonus to see if it helps. Mayve Bob can use his amazing cluster to see the effect...it might be small and require a lot of games.

During the midgame, a tempo appears to be worth about 9 centipawns.

I guess that the result will be specific to individual programs.

[bob]

Has anyone done testing on the Side to Move bonus, and if so, how much does it help (if anything)? It would seem simple enough to test some public source programs with and without the bonus to see if it helps. Mayve Bob can use his amazing cluster to see the effect...it might be small and require a lot of games.

It is _very_ small. I have one in Crafty. +5 for side on move in middlegame, +8 in the endgame. Worth a couple of Elo. And we spent a good bit of time testing different values to reach those as optimal [for crafty of course, YMMV].

[Jan Brouwer]

Has anyone done testing on the Side to Move bonus, and if so, how much does it help (if anything)? It would seem simple enough to test some public source programs with and without the bonus to see if it helps. Mayve Bob can use his amazing cluster to see the effect...it might be small and require a lot of games.

Rotor uses a bonus of 5 cp, this was roughly the optimum when minimizing tree search sizes for the LCT II set of positions.

[bob]

Has anyone done testing on the Side to Move bonus, and if so, how much does it help (if anything)? It would seem simple enough to test some public source programs with and without the bonus to see if it helps. Mayve Bob can use his amazing cluster to see the effect...it might be small and require a lot of games.

Rotor uses a bonus of 5 cp, this was roughly the optimum when minimizing tree search sizes for the LCT II set of positions.

Not sure how minimizing search space infers anything at all about an optimal value for any scoring term...

[Ryan Benitez]

The side to move bonus values are the only eval values that are the same in Fruit now as they where in Fruit 2.2 and it makes a huge negative difference to take the bonus out. I have always been uncomfortable with a huge side to move bonus but in Fruits case it works. I am sure there is a better why to do tempo I just have not figured it out myself yet. Maybe some type of table full of move bonus scores for each to and from for each piece given the game phase. Also some engines apply the bonus outside of eval so the bonus is not used for pruning decisions.

[Ryan Benitez]

Has anyone done testing on the Side to Move bonus, and if so, how much does it help (if anything)? It would seem simple enough to test some public source programs with and without the bonus to see if it helps. Mayve Bob can use his amazing cluster to see the effect...it might be small and require a lot of games.

Rotor uses a bonus of 5 cp, this was roughly the optimum when minimizing tree search sizes for the LCT II set of positions.

Not sure how minimizing search space infers anything at all about an optimal value for any scoring term...

Fewer nodes searched the less time taken. One would hope that is best solution sooner.

[michiguel]

Has anyone done testing on the Side to Move bonus, and if so, how much does it help (if anything)? It would seem simple enough to test some public source programs with and without the bonus to see if it helps. Mayve Bob can use his amazing cluster to see the effect...it might be small and require a lot of games.

Rotor uses a bonus of 5 cp, this was roughly the optimum when minimizing tree search sizes for the LCT II set of positions.

Not sure how minimizing search space infers anything at all about an optimal value for any scoring term...

There was a long thread started by Don Dailey some time ago. A given sidetomove bonus wll decrease the tree size because it smooth the jumps in eval from ply to ply. It is possible that this may be main the reason why a small bonus helps, at least a little. If that is the case, optimizing for tree size will be a good approximation for optimum strength..

Miguel

[Dann Corbit]

Has anyone done testing on the Side to Move bonus, and if so, how much does it help (if anything)? It would seem simple enough to test some public source programs with and without the bonus to see if it helps. Mayve Bob can use his amazing cluster to see the effect...it might be small and require a lot of games.

Rotor uses a bonus of 5 cp, this was roughly the optimum when minimizing tree search sizes for the LCT II set of positions.

Not sure how minimizing search space infers anything at all about an optimal value for any scoring term...

There was a long thread started by Don Dailey some time ago. A given sidetomove bonus wll decrease the tree size because it smooth the jumps in eval from ply to ply. It is possible that this may be main the reason why a small bonus helps, at least a little. If that is the case, optimizing for tree size will be a good approximation for optimum strength..

Miguel

Heuristically, we can also see that the calculation has created a value that is in line with that calculated by other approaches.

[Jan Brouwer]

Has anyone done testing on the Side to Move bonus, and if so, how much does it help (if anything)? It would seem simple enough to test some public source programs with and without the bonus to see if it helps. Mayve Bob can use his amazing cluster to see the effect...it might be small and require a lot of games.

Rotor uses a bonus of 5 cp, this was roughly the optimum when minimizing tree search sizes for the LCT II set of positions.

Not sure how minimizing search space infers anything at all about an optimal value for any scoring term...

It is a bit indirect, smaller search trees imply stronger play.
I see this bonus more as a smoothing factor, to make the score of a PV less dependent from whether the PV length is odd or even.