4 ms·

In the variant called suicide chess it's routinely possible for humans to recognize wins 30 moves in the future. I've seen strong players do this in fractions

In the variant called suicide chess it's routinely possible for humans to recognize wins 30 moves in the future. I've seen strong players do this in fractions of a second during lightning games. One factor contributing to this is a comparatively low branching factor in terms of raw move legality. But I think it's similar (maybe slightly lower) to the effective branching factor a grandmaster considers in regular chess. Another factor is that it's not necessary to see the actual moves. Humans can immediately evaluate patterns that have a known outcome that many moves in the future without needing to enumerate the exact moves of the principle variation in their mind. You might argue that this isn't really what is meant by "x moves ahead". But I think this more "fuzzy" definition may very well be more accurate.

Perceval 17y ago
In Gödel Escher Bach, Hofstadter has three sections on "chunking." Chunking is distinguished from the type of branching calculation of future moves. Rather than evaluating linear move-countermove-move branches, humans can also evaluate in terms of previously recognized patterns or configurations of pieces [essentially what you're talking about, mightybyte, if I understand you correctly]. This kind of pattern recognition or pattern seeking is a substantial shortcut, reducing the amount of mental computation necessary in branching approaches. It's also an area in which human still potentially retain an efficiency advantage over computer opponents like Deep Blue. There's some explanation on Wikipedia: http://en.wikipedia.org/wiki/Chunking_(psychology) http://en.wikipedia.org/wiki/Chunking_(psychology)