Toga II 4.0 release

[jd1]

Dear all,

Happy New Year! It is my pleasure, after a break of several years from computer chess, to release Toga II 4.0.

Strength

Self-play results:
+80 elo at 4' + 0.04' on 1 thread after 4000 games
+85 elo at 10' + 0.1' on 4 threads after 2000 games

Nice job.

Some months ago, just for the fun of it, I looked into the eval of Toga II 3.0 and found some improvements. By head I remember -

#1. Instead of fixed values for isolated and backward pawns use a PST.

#2. Remove the own pawn support bonus for knight outposts.

#3. Bishop pair via table[number of pawns] instead of fixed values

#4. Bishop mobility, instead of only looking at the 2 forward directions do all 4 directions after all

#5. Also throwing out the 2nd Lazy Eval Cutoff gave elo.

Wasn't able to improve on King Safety, hated that.

Thank you so much Ed!

I will try #1 to #3, #1 and #3 in particular seem like they should be worth significant Elo.

Toga II 4.0 already incorporates #4.

As for #5, could I please ask how many games you tested it with and at what time control? I twice ran tests to try to cut it out ~(3000, then 8000 games at 3' + 0.03') but never managed to get even a plus score by removing it.

Code: Select all

#define LAZY_EVAL_2		OFF			// 51.0% | los=95.3% 

is all I have. I usually play 4800 games at 40/60 in case of search changes, so 1.5 sec per move average.

Thanks Ed. That's a far longer TC than what I used, that must be the reason. Lazy eval doesn't tend to scale well in Toga II at least.

At 18-19 ply depth (Toga II v 4.0) Toga is now quite dangerous opponent for almost any chess engine in the world...Undefeated in my current RR tourney after 7-8 rounds....Look Out!!

Thanks

CEGT just released their result, +51 elo to Toga II 3.0 and the strongest Fruit derivative.