To use a simple example, tablebases show that KQ vs. K is won in at most ten moves. But chess books going back many decades, well before tablebases, say the same thing. How was this calculated?

2 Answers 2


Nothing was calculated. They arrived at their results by trial and error.

Some guy would start with a seemingly disadvantageous position and tried to find the shortest mate. His result remained valid until the next guy found a more disadvantageous position or a quicker mate.

A long time later, engines became powerful enough to calculate simple endgames like K+Q v K simply by exhausting all possibilities, but by that time technology was also advanced enough to create the first tablebases.


Well, it is calculated by tablebases. I can't imagine anybody declaring a definitive number for the minimum moves needed to achieve checkmate with KQ vs. K.

  • 1
    Well, then you should look into some old books ... ;-) Jan 28, 2017 at 8:30
  • 1
    The same books that claimed K+Q vs K+2B to be a draw?
    – Glorfindel
    Jan 28, 2017 at 9:20
  • 2
    To be fair, there is a big difference between KQ-K and KQ-KBB. But yes, those books. Jan 28, 2017 at 10:29
  • And how useful are those numbers? If you can mate with KQ vs K in about ten moves, you know you understand it. Likewise if you can consistently do KBN vs K in less than 50. There is nothing comparable for KQ vs KBB. The useful information was on the whole produced mostly by human beings. Admittedly, KQ vs KR is a marginal case. And, yes, I do know about John Nunn's work.
    – Philip Roe
    Jun 9, 2017 at 16:15

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.