Where do you get the number 6 from? And what do you mean "away from the root".Daniel Shawul wrote:Well I already mentioned to Adam syzygy is probed much less frequently than I did because it probes 6 plies away from the rootTo note that SF Scorpio had a dramatic loss in NPS, on average by a factor 1.7 or so.
My implementation probes whenever remaining depth is at least SyzygyProbeDepth which by default is set to 1. This means it probes everywhere in the regular search (not in the qsearch). If only 5-piece tables are probed, SyzygyProbeDepth should be set to 1 since the WDL tables should easily fit in RAM. NPS should not be affected much (except maybe in the first seconds while the OS pages the tables into the page cache).
There is certainly no minimum number of plies "away from the root" since the closer to root the better.
The exception is probing WDL when the root position is already in the tablebases, since probing immediately would basically lead to random play without progress. In this case I probe immediately after a move that is known to make progress (provided it is winning), i.e. a capture or pawn move. This exception applies only if DTZ is not available.