In some cases, continuously fighting in a drawn position against a computer programmed for imperfection will cause the computer to play a nonsensical move. Here is an example against Boris on Sparkchess.com.
After Kh7, I went on to win easily. Both me and the computer played very well up to that move, but the computer was programmed to not play perfectly. The computer played the later part of the endgame with an extremely small centipawn loss because almost all moves preserve equality. After a large number of perfect moves in the endgame, it was programmed to play an imperfect move. The only imperfect move was a blunder that lost the game on the spot.
The Stockfish Engine on lichess is different because the lower levels have reduced processing power instead of being programmed to intentionally make mistakes.
After Kh7, I went on to win easily. Both me and the computer played very well up to that move, but the computer was programmed to not play perfectly. The computer played the later part of the endgame with an extremely small centipawn loss because almost all moves preserve equality. After a large number of perfect moves in the endgame, it was programmed to play an imperfect move. The only imperfect move was a blunder that lost the game on the spot.
The Stockfish Engine on lichess is different because the lower levels have reduced processing power instead of being programmed to intentionally make mistakes.