This is no mate. It is a curious 5-fold repetition, which would have been a draw after the first 3. The computer did not recognize it as such, and neither did the programmer, aparently.

It seems to me that this mistake begins when the King moves to g4, already occupied by the Bishop. If we substitute a legal move, such as Kh4, the play could have played out to mate. But this mistake continues in the Knight moves, which instead should have continued the pattern already established, which would have then resulted in mate at move 37, anyway.

My question is rather on several of the previous positions, which have the Black King moving in ways that seem to facilitate his own demise. I am now wondering if the program was hastening toward a stalemate position instead of attempting to survive 50 moves? This latter objective is the principle subject of our investigation, after all. /Fx/