Slow Chess Blitz Classic 1.8 is now available : https://www.3dkingdoms.com/chess/slow.htm
- Thoroughly reworked a lot of code, and tweaked eval, but not sure what specific to mention.
- Further increased value of king safety/checks, pawn promo threats, and some other threats. (Realized with modern search this helps to follow threats even if values seem too high to me.)
King safety is getting pretty aggressive for near term danger, but accuracy isn't great. And still needs work building to an attacking position (and also to be better at building positional advantages to press, which sometimes creates weaknesses leading to attack.)
- Optimized code to be about 20% faster + changed Threat Moves to detph > 3 to minimize slow-down and be more about not missing something. Seems the hard-coded threat move detection is only a small elo increase at this point, though hard for me to measure.
- Did a code cleanup pass to prepare for multi-threading and code portability. Maybe version 1.9 will support multi-threaded search.
I realized I still don't do nearly enough testing to estimate strength accurately, I was trying lots of changes for no consistent improvement for last couple weeks. (Lot of variation in 500 game matches, then even much more when I added variety of opponents), but it was always stronger than 1.7, with a few scattered extra good results. (Realistically hoping for around +35 elo, though did have some better runs.)
My current plan is trying to add parallel search for a version 1.9 that probably will otherwise be similar to 1.8. That seems like a good way to close out the modernization of Slow Chess for the Classic for the 1.x series.