PZChessBot 2.0 JA - new version chess engine

PZChessBot is a basic negamax engine.

Author: Kevin Lu 

v.2.0 What's Changed

bench: 120629 add lmr to main by @kevlu8 in #33

Add output buckets to NNUE by @kevlu8 in #34

bench: 299703 tune network on .65 wdl by @kevlu8 in #35

bench: 309079 fully retrain network with low wdl by @kevlu8 in #36

bench: 273173 add history by @kevlu8 in #37

bench: 273173 Switch to proper move ordering scheme by @kevlu8 in #38

bench: 273173 add pv printing by @kevlu8 in #40

bench: 184778 add counter-move history by @kevlu8 in #41

bench: 96074 add IIR by @kevlu8 in #42

Fix 50-move rule handling - also fixes a part of illegal PV by @kevlu8 in #43

Add reverse futility pruning by @kevlu8 in #44

bench: 63404 disable nmp when pieces < 8 by @kevlu8 in #45

Add EGNN evaluation for positions under 12 pieces by @kevlu8 in #47

Prevent storing of the same killer move by @kevlu8 in #48

bench: 192920 fix pvs pv issue, also partially fixing low nps issue by @kevlu8 in #50

Should be around 3100 strength... I forgot to release so this is long overdue but its ok!

PzChessBot 20250311T07 JA vs other engines:

Melsh Bot 1.0 JA	3/4	+2	4 Games
Maello 0.1 JA	1/4	-2	4 Games
Critter 1.6a	0/4	-4	4 Games
Rodent IV 0.33 JA	0/4	-4	4 Games
Princhess 0.20 JA	0/4	-4	4 Games
Perseus 1.0 JA	0/4	-4	4 Games
Seawall 20250322 JA	0/4	-4	4 Games
Renegade 1.1.98 JA	0/4	-4	4 Games
Chesslib 0.0.3 JA	0.5/3	-2	3 Games
Victoria 0.1 JA	2/2	+2	2 Games
Ultrabrick dev.bd5adb0 JA	2/2	+2	2 Games
Gravy 1.0 JA	2/2	+2	2 Games
Kopyto 0.1.0 JA	1/2	+0	2 Games
Meltdown 0.1 JA	0.5/2	-1	2 Games
Limbobot 0.1 JA	0/2	-2	2 Games
Chess-3 JA	0/2	-2	2 Games
Cinder 0.1.3 JA	0/2	-2	2 Games
Dumb 2.3	0/2	-2	2 Games
PlentyChess 5.0.0	0/2	-2	2 Games
Quanticade Fenrir 1.0 JA	0/2	-2	2 Games
Shallow Guess 0.1.0 JA	0/2	-2	2 Games

Windows/Linux & Android profiled builds - Jim Ablett compiles:

PZChessBot 2.0 JA download

Successes of the PZChessBot engine in our tournaments:

PZChessBot 20250421T23 JA wins Amateur League group E-08 Season 04/2025