Informator symbols and centipawn evaluations

Is there some sort of concensus on how informator symbols relate to centipawn evaluations? That is, a guiding rule to how many centipawns translate to, say += etc.

Very roughly, an evaluation around +0.50 may be +=, around +1.00 may be +/-, and around +2.00 (and larger) may be +-.

Details will depend on the engine giving the centipawn evaluation.

Great! Very useful guidelines!

Follow-up question: Which magnitude in change of evaluation would qualify a move as a "?" etc...

That will depend on the person commenting on the game, of course. It will also depend on the evaluation region this takes place at.

Dropping from +9.00 down to +4.00 may make no difference at all for the outcome of the game (white is still clearly winning after that), so it may not really merit a question mark in the eyes of many.

Dropping from +4.00 down to +1.00 may be a question mark for many, although some would say it is merely ?! for example when the resulting position is still technically winning for white anyway.

Dropping from +1.10 down to +0.10 is clearly a ? in most cases (except the engine evaluations are not accurate, for example in some endgames it does not properly understand), since it turns a probable win for white into a probable draw.

Does this give you a good general idea?

Sure! Interesting comments. My gut feel was that any move that looses a winning advantage or creates a loosing disadvantage would be ??

I suppose I am inclinded to use ? more often.

Again, thank you for valuable input.

farbror wrote:

Is there some sort of concensus on how informator symbols relate to centipawn evaluations? That is, a guiding rule to how many centipawns translate to, say += etc.

In Chessbase/Fritz, it looks like +- appears when the engine is returning an evaluation greater than 1.39 centipawns.

± between 1.39 and 0.70

⩲ between 0.69 and 0.26

= between 0.25 and -0.25

⩱ =+ between -0.26 and -0.69

∓ between -0.70 and -1.39

-+ less than -1.39

Aquarium and Chess Assistant seem to follow similar ranges while Arena, Hiarcs Chess Explorer, SCID, Shredder and Winboard don't seem to use the Informant symbols.

farbror wrote:

Follow-up question: Which magnitude in change of evaluation would qualify a move as a "?" etc...

In Fritz's full game analysis, if you set it to "verbose," it puts ?? after blunders, and ! after good moves, but doesn't seem to make any finer distinctions. GM Robert Huebner used ? for moves that turned wins into draws, and ?? for moves that turned wins in losses. In endgame books by John Nunn and Karsten Muller, they would use ? for moves that turned wins into draws or losses, ?? for bad moves, and ?! for moves which made the player's task more difficult.

Wayne_Thomas, going into such details will be a bit over the top for most purposes. These details will likely be different for different engines, just as different engines may have different evaluations for a position.

And while ? is used to indicate a bad move,

?? is usually simply used for bad moves that one feels emotional about.

CM ilmago, thanks for the feedback. Farbror seemed to be asking about the specific range for each symbol, so that got me curious. Positional evaluation is probably not the strong point of engines in any case, so I agree that you have to take all of this with a grain of salt. I do find it kind of interesting though to see how programmers try to operationalize factors that are hard to quantify. Even if a particular engine ends up steering you in the wrong direction sometimes, what constitutes a "slight advantage" or a "bad move" remain worthwhile questions I think.

Jonathan Rowson and Alex Yermolinsky talk a bit about the role of emotion in evaluation in their books.

The connection between a specific number and the evaluation of a position in words is of no real meaning for engines. All engines really need to try to do is to say (using numbers) which position they like more than another, so they can choose a move.

Even assuming two different engines are steering along the best moves in a position, they usually will do so using different numbers for the same position.

I think farbror in his questions is trying to come up with a method for annotating games.  ilmago, I understand and agree with your point that human annotators do things differently, but on the other hand, it also seems worthwhile to try to make the definitions of various symbols more precise.  Programmers may disagree on how to assess positions, but that's part of the interest I think.

I do not think he is. Look at the time of when he wrote his questions, and look when he stopped asking further, satisfied with the answers.

Do not try to be more precise, you will be more wrong the more you try to. Engines are quite different in that very aspect.

Anyway, I was just trying to be helpful.

Yep, next time maybe try to help people whose question is younger than 4 years old --- and of course beware that overshooting towards being more exact than it makes sense can actually be less helpful.

My apologies if answering old questions runs against forum etiquette.  I was actually annotating some games on my ipad, started wondering what +=, =, =+ et al meant, and came upon this thread through Google.