Eubos 4.3 JA - new version chess engine

Eubos - a basic Java chess engine, written for kicks. Uses jcpi for the UCI protocol parts. Kind of weak, doesn't evaluate for king safety, for example. Now uses transpostion hashing, but because it runs in the Java VM on a bog standard PC, doesn't search very deeply (around 100K Nodes/s, though this is actually quite hard to evaluate due to the hashing). 

Author: Chris Bolt Rating CEDR=2493

Eubos 4.3 what's new?

Main effort was to optimise board updates when playing moves and to fix a bug in multithreading which meant that any extra thread from the main used the wrong hash after a castling move occurred in the game, thereby ruining the effect of lazy SMP. I spent a lot of effort trying to not update the iterative neural net evaluation when a move resulted in an insufficient draw, but this had negligible, perhaps detrimental effect, so that work was reverted.

Aslo, the neural net was retrained using the same training data as per v4.2, but with a smaller batch size, resulting in a small strength improvement by reducing over-training. I am still experimenting with the learning rate scheduler to optimise performance for this training set.

Eubos 3.9 JA vs other engines:

Pioneer 0.3.2 JA	4/4	+4	4 Games
Mufasa 0.2.1 JA	3.5/4	+3	4 Games
Integral 7.0.0	0/4	-4	4 Games
HypnoS ++ 1.02	0/4	-4	4 Games
GOOB 1.8.9 JA	0/4	-4	4 Games
Peacekeeper 3.01 JA	0/4	-4	4 Games
Odonata 1.0.0 JA	0/4	-4	4 Games
Obsidian 15.03 SE	0/4	-4	4 Games
Killfish PB 090225	0/4	-4	4 Games
Midnight 9 JA	0/4	-4	4 Games
Fatalii 0.9.0	0/4	-4	4 Games
Beef 0.3.6 JA	0/3	-3	3 Games
Bitbit 1.3	2/2	+2	2 Games
Rustic Alpha 3.05 JA	2/2	+2	2 Games
Reggz 0.6.0	2/2	+2	2 Games
Deep Blunder 1.2.0 JA	2/2	+2	2 Games
Jester 0.85 JA	2/2	+2	2 Games
Sloth 2.0 JA	1.5/2	+1	2 Games
100 Elo Chess Engine	1.5/2	+1	2 Games
Fatalii 0.9.0 JA	1/2	+0	2 Games
Stro4k 3.0 JA	1/2	+0	2 Games

Jim Ablett compiles:

Eubos 4.3 JA download