The TBs inform the engine that the position is a loss, blessed loss, draw, cursed win or win. It is up to the engine programmer to make use of this information. If the engine is playing white and the position is a blessed loss for white, then the engine can safely score the position as a draw (but I would personally prefer scoring it as -0.01 so that engine prefers "real" draws). If the position is a cursed win for white, then the engine should score it at least slightly positively (unless it is certain that the opponent is using 50-move aware TBs too or it is known that the game will be (correctly) adjudicated).Lyudmil Tsvetkov wrote:rigth, the last move must be a capture.
essentially, what changes this though? any tbs mate longer than 50 moves will be considered as a draw, this node will return a score of 0.0, while another node, with no tbs hits and a score of, say 40cps, objectively a draw in the eg, will be considered by the engine stronger than the 0.0 cursed win node.
Objectively a cursed win is very much a draw. A simple mathematical fact.this definitely has implications on choosing the best move. why consider a node that is draw with slightly positive score better than a node with 0.0 score, objectively though a win?
In practice when playing an engine not using TBs, and certainly when playing a human, the position can likely be won because the opponent will play imperfectly. So in that case the engine should probably assign it a score that reflects its very real winning chances.
Influencing the decision on what move to play is the point of using TBs.during search, an engine might hit hundreds of thousands similar cursed win nodes, and take decisions accordingly. the impact on game play should not be small.