If you have experience playing against these programs you will note that a human might resign earlier. Toward the end of a game that it will lose the program will make "insulting" attacks, play moves that will work only if responded against very poorly or not at all. The reason is that from its calculation the probability of that isn't zero. With experience playing against these programs you will learn to recognize when close to the end of the game whether the program "thinks" it will win or lose. Unnecessary safety moves that cost a point or two means the program has the game in hand while attacks that would work only against a bad mistake means the program "knows" it has lost.