All Questions
12
questions
-2
votes
1
answer
266
views
Why does Stockfish miss mate in 5 with only two legal moves?
I'm interested to understand what is going on for Stockfish on Lichess here. There are only two legal moves for Black, and it gives the position mate-in-14 for white.
When asked to play its ...
- 3,340
2
votes
1
answer
105
views
Testing Mate Possibility Without Use of King
I would like to be able to convince myself of the possibility (or lack thereof) of mate using various piece combinations in which the attacker doesn't use their own king.
I'd like to approach this by ...
- 359
1
vote
1
answer
264
views
Average number of moves until checkmate for two players of unequal strenth
Suppose a game is played, until checkmate, between players of unequal strength, say 1800 vs 2800. What would be the average number of moves be for, say, 1000 games? I also ponder 2000 vs 2800 and 2200 ...
3
votes
1
answer
403
views
What does an engine do if it has found the shortest mate?
For example, take this famous position from Kramnik vs. Deep Fritz, 2005:
[FEN "5N1k/6p1/7p/4P3/pp2Q3/4q3/1P4PP/2b4K w - - 0 1"]
Obviously White wins with Qh7#, and equally obviously, there ...
- 28.1k
2
votes
1
answer
767
views
Chess engine does not go for checkmate
I have made a chess engine that can play a decent game of chess. Like a lot of engines it uses a minimax search algorithm with alpha-beta pruning. It uses this simple evaluation function to assign a ...
- 29
20
votes
4
answers
7k
views
How often do grandmasters miss checkmate?
Although top players are extremely good at finding checkmate, the number of permutations of moves in just 3 moves can be hundreds of thousands, and the farther out the possible mate (e.g. mate in 4, ...
- 2,127
6
votes
4
answers
2k
views
What is the farthest away a game can be from a guaranteed checkmate?
What is the maximum number of moves away from checkmate that a player can be where checkmate is guaranteed? There are many positions that are a guaranteed win for a player if played perfectly, right? (...
5
votes
1
answer
696
views
How are chess engines able to rank a Mate in X above a Mate in X+Y?
According to an engine, a mate in X moves = +infinity, since it is a forced win for it.
Also according to an engine, a mate in X+Y moves = +infinity, since it's a forced win (just more moves, but an ...
- 19.9k
3
votes
2
answers
630
views
Why continue to increase search depth after mate is found?
Playing with test sets, several times I come across a behavior of the chess engines which I can't understand: Let's say I have the endgame
[FEN "8/k7/3p4/p2P1p2/P2P1P2/8/8/K7 w - - 0 1"]
which after ...
- 33
4
votes
2
answers
589
views
how to evaluate the position inside the search function
using PVS Algorithm with Quiet search and zero window search what should the range of the score be (-infinity, infinity ) could it be as small as (-16000,16000) and what should the search return if it'...
- 91
10
votes
2
answers
2k
views
Forced checkmate examples where engines fail
Do you know example where recent chess engines (Houdini, Rybka, Komodo, ...) failed to find a forced checkmate.
I guess they must find mate in 1 or 2 all the time but maybe are they failing to be as ...
- 935
1
vote
1
answer
500
views
Is my engine working properly?
I noticed that when I put my Houdini 3 Pro x64 in the "Infinite Analysis" mode, he tends to use a lot of time to evaluate the bad moves... Sometimes he even uses like 30 seconds on the first 10 best ...
- 4,894