Can anyone provide me with a link or short explanation for how to read chess analysis output from an engine.
I have been playing/analyzing with Arena/Stockfish lately, and while I understand the gist of what is being displayed when I make a poor move, what exactly are all the numbers coming out on the display?
Originally posted by trh178 Can anyone provide me with a link or short explanation for how to read chess analysis output from an engine.
I have been playing/analyzing with Arena/Stockfish lately, and while I understand the gist of what is being displayed when I make a poor move, what exactly are all the numbers coming out on the display?
if you are losing because of large margins in analysis -3 say, then it is a tactical mistake and it is best to try to search for it before clicking on, if you are losing to very small increments -0.02 say you need to look at positional aspects. I understand that this is really simplified, but what else can an engine tell you for it doesn't understand strategy.
I've stopped playing chess at work (the boss comes round the corner and I end up throwing the game), so instead I let Fritz 12 and Rybka 4 play blitz matches against each other.
The results are interesting. In many games Fritz will have a disadvantage against Rybka, but he is a little bit more optimistic about it and gives himself a higher eval than the fish. Might have something to do with the fact Rybka calculates more play than Fritz. This also accounts for most of Rybka's losses against Fritz as they are almost always due to time.
I guess the point is that engines looks at things differently, but almost any one usually comes up with stronger moves than a person, but none of the will ever have as much fun.
The number usually relates to an advantage measured in Pawns. Everything else in a position might be equal but you might have a Rook on the 7th rank, something an engine MIGHT regard as an advantage equivalent to being 2.5 pawns up. The number displayed might then be 2.5 to signify this.
If we take the same position and say that you have that rook on the 7th, but you sacrificed a pawn in order to get it, putting you a pawn behind, the engine might evaluate the advantage as 1.5 pawns up. The given score is thus an aggregate of not just the material imbalance but all the positional factors which that engine can evaluate.
There is another detail - most engines assign negative values for an advantage to black and positive for white. So a score of -2.5 means that Black has an advantage equivalent to being 2.5 pawns up. A score of 2.5 means the same advantage to White.
A score of 0.00 signifies that the engine thinks the position is dead equal. We could use a shorthand symbol '=' to indicate this 'balance'. An engine might use a '+=' to signify that the advantage has swung in Whites favour, and '=+' the same for Black. Fritz does this in it's annotations (if i remember right.) A winning advantage is shown as a heavier inbalance such as '++=' or '=++'.
Other numbers in engine analysis usually relate to the depth (how many moves deep it's looked into a position) or the time it's taken to arrive at an evaluation.
Originally posted by Deau The number usually relates to an advantage measured in Pawns. Everything else in a position might be equal but you might have a Rook on the 7th rank, something an engine MIGHT regard as an advantage equivalent to being 2.5 pawns up. The number displayed might then be 2.5 to signify this.
If we take the same position and say that you have that rook on the 7th ...[text shortened]... p it's looked into a position) or the time it's taken to arrive at an evaluation.
How to read chess engine analysis
25 Oct '10 17:40
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