Repetition Puzzle

CybernetRecover

Where should black go for his 5th move? Can your chess engine give the right answer?

Arisktotle

Engines in general will go for the wrong answer Kb1 as it mates 1 move quicker. I suppose it depends on whether they are playing a game or just analyzing a position. SF Analysis certainly doesn't look back and often advises endless repetitions itself in postions it should win in a different way. Doesn't like to give up a material advantage for a win, strange as it sounds. That is until it detects a concrete mate on the horizon!

Context matters. Rules around repetitions in games have changed but these changes were not always reflected in "problem" environments. In areas like retrograde analysis discussions have been going on for years about how to interpret the repetition rules exactly. What context should Analysis be supporting?

Collection_Agency

welcome back! really missed you these days

I guess that black pawn is queening. What engine did you use?

Arisktotle
Collection_Agency wrote:

welcome back! really missed you these days

I guess that black pawn is queening. What engine did you use?

Never been away really but I am the either stop or run type of person. Don't be surprised when the lights dim down again tomorrow. And do not conclude they have gone out!

I have always been low on computer tools and that applies to engines as well. Currently I only use Stockfish on chess.com which is a pretty good engine compared to some I tried in the past. I was told though that Fritz behaves similarly to SF on repetitions and I can understand the logic behind engine reasoning. The situation would be different if repetition was strictly prohibited (like in Go). As things stand now, repeating is a free shot at getting an even better result so why not try it?

Similar behaviour reigns the sacrificial underpromotion. You see 'serious' engines executing a Bishop promotion on the assumption that not capturing the bishop gives an even better result than capturing it and it will give you the opportunity to go wrong. AlphaZero won a game against anothe engine by a sacrificial Knight promotion which was not consumed. The logic here is flawed though as it assumes own perfection and it might bounce back against a superior opponent.

MarcelinaG

ok