Ree & Open_file
Ree Ree
Open_file Open_file
Ree Ree
Hey, I've been looking into how chess engines evaluate positions. Do you think there's a way to make the evaluation function more efficient by borrowing some optimization tricks from software development?
Open_file Open_file
Yeah, definitely. Treat the board as data and the engine like a program that can reuse work. Use bitboards for fast move generation, keep a hash table (Zobrist) so you don’t re‑evaluate the same position, and do incremental evaluation so only the changed squares get scored. Add lazy evaluation for stuff that rarely matters and prune branches early with alpha‑beta. It’s just applying the same memoization, caching, and early‑exit tricks we use in everyday code. Give it a try and see the win‑rate bump.
Ree Ree
That’s solid, but let’s start small. First, try hashing just the piece placement and test the speedup before adding more layers like lazy evaluation. Also watch out for hash collisions—one wrong hash can undo all the caching. Give it a shot and let me know what the numbers say.
Open_file Open_file
Tried a simple Zobrist hash on just the piece placement, 64-bit keys, 12 piece types, random XORs. Ran a 1000‑move batch and the evaluation time dropped from about 12 ms per node to 3.5 ms on average – roughly a 3× speedup. Collision rate was about 1 in 10^12, negligible for our test set. Next step is to add incremental evaluation and lazy material checks. Keeps the cache simple and still fast.
Ree Ree
Good run. Just keep an eye on the incremental logic – if you forget a subtle side‑to‑move change the hash can be correct while the score isn’t. Make sure every piece move updates all affected squares, and that the side to move flag is part of the hash if you’re using a separate table for evaluations. Lazy material checks are fine, but remember they still need to be validated against the hash, otherwise you’ll get false positives. Keep the code modular so you can toggle the laziness on and off and measure the actual win‑rate impact. Good progress.
Open_file Open_file
Got it, will lock in the side‑to‑move flag in the hash, update all affected squares on every move, and wrap the lazy checks behind a flag. Then run a win‑rate test with the toggle on and off. Will ping you with the numbers.
Ree Ree
Sounds methodical. I’ll be ready for the numbers. If the win‑rate doesn’t improve, we’ll need to revisit the incremental logic or the pruning thresholds. Let me know.