Sorry for bringing up an old thread but I am still struggling a bit with mate scores. I understand that you need to fix a mate score when retrieving or adding it to the transposition table. But should you also do this if it is not an EXACT score? I guess not (but I could be wrong...).

The reason ...

Sorry for bringing up an old thread but I am still struggling a bit with mate scores. I understand that you need to fix a mate score when retrieving or adding it to the transposition table. But should you also do this if it is not an EXACT score? I guess not (but I could be wrong...).

Any bugs found? My engine takes 15 minutes for the first ply which is too long I guess...

Yesterday I implemented Bruce's code and I am also writing the PV back to the hash. But what do you mean by this regarding Stockfish: 'but with values that will cause the entry to be ignored for cutoffs'?
And you are updating your "always" hash only if the score is better. But what do you mean by ...

Bruce's code saves the PV going down the search tree, saving the best line each time alpha is raised, but once back to the top, what to do with it?

at first I was just using it to pass on the best "line" to the GUI, but after examining some Stockfish code, I saw where they write the PV back to the ...

Most engines of course do not get the PV out of the hash table, so that storing QS in the TT is really a separate issue. Retrieving it from the hash almost never leads to the node that provided the score, even if you did store QS nodes.


I DO get the PV from the hash-table and was wondering if I ...

Kudos, seems like a very well written program.

Did you get your evaluation tables from other sources or from your own game knowledge?

Also, I've been wanting to cache moves generated at the corresponding hashing key (and why not in a persisent table) to gain a lot of time during the search, but ...

Very nice. But remember that this is a hobby that you almost exclusively do for your own satisfaction. The demand for engines that play orthodox Chess is close to zero, (and there already are thousands on offer), unless they are within a couple of Elo from Stockfish. There is a (quite small ...

I just released the first version of my engine on Github on which I have been working for about a year. See:
https://github.com/sandermvdb/chess22k

This has been my 2nd engine. About three years ago I started building an engine which the basic knowledge I had; I could program and I could play chess ...

My engine which uses a bitboard and is also written in Java gives the following results on an Intel Q9550 (2,83 Ghz):

QPerft 5: 264ms
QPerft 6: 2948ms

Perft 5: 3069ms
Perft 6: 75648ms

QPerft is without making the last move, Perft is with.



CORRECTION:
Perft does NOT make the actual move ...