WChess PV settings

[jcgdijkstra]

Does the PV setting (0-3) in the old WChess DOS program influence the playing strength (i.e. move selection) at all or is it only used to show the best move analysis?

[Eelco de Groot]

Hello jcg,

I don't know Dave Kittinger's program, but from the sound of it this looks like a form of Multi PV. For an alpha beta program, rule of thumb says that about half of the time is spent in the PV, rest in exploring the other rootmoves. If you want two PVs the time to reach the same depth will increase therefore with 50%, 150% of the time it used before to reach the same depth. For three PVs it becomes roughly 200%. In a game, this will lower playing strength accordingly but you have more information on what is likely the second best move etc. and sometimes it will find a better move this way.

[jcgdijkstra]

Thanks Eelco