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I copy pasted your code in my solution. But speed got much worse. Factor two. Don't know what caused it. Oops, I guess that's because I left a little trap for you in my code snippet :lol: // NOTE: // I suggest to switch the order of "i" and "stage" in the return tuple for consistency with the // or...

[...] nested ?: at the last statement of this method are hardly readable. (IMovePrioQ, IMoveBase, int, int) NextMove( SearchParam p, IMovePrioQ prioQ, int stage, int i, bool allowStandPat) { var end = i >= prioQ.Count(); var (j, nextStage) = end ? (0, stage+1) : (i, stage); var nextPrioQ = (end && ...

The copy&make approach is not necessarily "too expensive". You could certainly optimize your implementation by using 8 bitboards instead of 13, and also by using a slightly more efficient copying technique than a loop (e.g. memcpy() in C). But in general that approach can work equally well compared ...

Looks like I'm an expert in writing horrible code. For instance this one. I mean nested ?: at the last statement of this method are hardly readable. Not the only reason ... Recursive call of NextMove()? Why? What is the purpose of variable "j"? Maybe choose a better name ... "i" can be understood f...

Hi Graham, thank you for this great tournament. I have tried to connect to GrahamCCRL.dyndns.org, Port 16001 with the Chess viewer, but I get a "Connection failed. No response from server." each time. Can you help? Thank you! Hi Oliver, connection issues are usually to do with either firewall or ro...

The typical pattern applied in many engines is as follows: - In the tree, mate scores are relative to the root node. When detecting a mate ("mated in 0") you return -(MATE_VALUE - ply). When seeing a mate score returned from a subtree you either see a negative score ("mated in N" with even N) or a p...

Furthermore, I do not fully understand your code regarding the side to move and the viewpoint of the static evaluation. I see three terms: 1) pos.analysisPlayer, which seems to be the side to move at the root node (but why do you still need to maintain that, after having switched from minimax to neg...

In mtfd(), when changing -abm(...) into +abm(...), did you also remove the color switching in the function call (1-.....)?

The +abm() must be correct. In Negamax you negate the result of searching a child node where it was the opponent's turn. But in mtdf() you call abm() still at root so there is nothing to negate yet. Your Negamax happens inside of abm() only. Does your static eval return a score from the viewpoint of...

if(m.endPosition.eval > g){ tpMove[pos.hash] = m; pos.bestMove = m; g = m.endPosition.eval; } if(g > a){ a = g; tpMove[pos.hash] = m; pos.bestMove = m; } You only have a PV (and therefore a best move) if its score is within the alpha/beta window. Therefore you should only store the best move if (g ...