During the Div4 tournament I had been experimenting with the search part of rofChade together with the added evaluation terms. Version 1.0 only had material and Piece Square Tables for evaluation, but with the added evaluation elements it seems that LMR reductions can be a more aggressive than without the eval terms. Probably the move sorting of the quiet moves becomes a bit more accurate with more eval.
The version with more aggressive LMR seemed a bit better and I had also been playing with the usage of the hash table in quiescence search. Because the TCEC tournament runs on a dual processor machine with 44 physical cores, I thought that not using the hashtable in quiescence might be better. Testing on my Threadripper 1950X showed some elo gain.
So eventually I decided to play with the new version in Div3. In Div3 the new version performed fairly good. Not using the hashtable in quiescence made the NPS go up from 58M to around 73M in the opening phase, but with lazy SMP more NPS not necessarily means better. Eventually it lost too much games in the last round and ended sixth place. Lc0 and Komodo MCTC ended first and second and where too strong for the rest of the Division(also for Div2 in which they also finished first and second).
The difference between places 3 to 6 was just 0.5 point, and because rofChade crashed one time in a dead draw endgame against Arasan and the TCEC tiebreak rules it ended up sixth.
Fortunately I was able to find the bug that caused the crash, so that crash won’t happen again in the future.
Sixth place ensured a stay in Div3 for the next season, so hopefully rofChade will do even better then!
