TalkChess.com

Not sure this is "news". In the early 80's, I might win one out of 100 games against Cray Blitz, yet our ratings were pretty equal in terms of USCF. 5 years later, that was zero out of 100. Been that way all the way through current Crafty. It is really easy to develop an engine that beats you trivia...

Here's the reason for overwriting. Apparently whatever is there was not good enough to terminate the search at the start of this position, so what's the point of saving something that didn't work when you now have something that is correct and useful?? IE exactly what HGM said but with fewer words.....

Recursion has worked for a long time now. One thing to avoid is a 2d array, use a 1d vector instead. Otherwise every array access ends up with an integer multiply buried in the middle of the address calculation. Otherwise it will work fine. The language is a bit of a mismatch for chess but I used it...

This is a problem you have to fix. If your opponent plays a move that "undoes" one of his recent moves (or his most recent move most commonly) then you will find that position in your book if you are not careful to recognize the 2-fold repetition. My fix was to simply ignore a book move that repeats...

Another thought. NPS is highest when you do a pure minimax search. You don't waste any computation effort generating moves or doing other things that cost computational effort. As you improve ordering, you begin to see NPS drop because in lots of positions you just search one move and throw the rest...

To 'compare' algorithms you should first define a metric for algorithmic complexity. You seem to focus (completely arbitrarily) on the number of multiplications. One might just as well only consider the number of branches. With the same number of branches per second, Stockfish would not be a match ...

My current "easy move" approach is really just a "easier/harder" approach. If things are stable, the situation looks "easier". If things are unstable, the situation looks "harder". That degree of stability can make the search move significantly faster, or significantly slower. Very "un-computer-like...

unless you have a power of 2 size, a table lookup is going to include a multiply. Shift and add really don't count in a super-scalar architecture. I don't think there is anything to gain here. I used to do what Slate and Atkin did. Maintained an array of attacks. One showing all squares attacked fro...

Getting rid of that overhead is what drove me to the rotated bit board development. And then magic move generation came along as yet another alternative. The updates to maintain both attacks to and attacks from (slate/atkin chapter in Frey's "Chess Skill in Man and Machine") were pretty expensive. C...

May or may not be what you want. RSS = Resident Set Size. This is the set of pages the program currently has in real memory. Might or might not be the actual "working set" as some of the pages might be swapped out. Also RSS is the set of physical pages in memory for a process. There can be overlap w...