What are computer evaluation numbers?
Computer evaluation numbers, often referred to simply as evaluations or evals, represent a computer's assessment of the current position in a game of chess.
They're derived from deep analysis using advanced chess engines, like Stockfish or Komodo, and they provide an approximate value for the advantage one side has over the other.
How to interpret the numbers
Value | Example | Meaning |
Positive values |
+2.25 | This indicates that White has an advantage. The higher the number, the larger the perceived advantage. |
Negative values |
-1.50 | This indicates that Black has an advantage. The more negative the number, the larger the perceived advantage. |
Values close to 0 | +0.20 or -0.10 | These suggest that the position is relatively even. |
What do the numbers actually mean?
The values represent material or positional advantage in terms of pawn units:
+1.00: White has an advantage roughly equivalent to being one pawn up.
-2.50: Black has an advantage roughly equivalent to being two and a half pawns up.
These evaluations aren't just about material. A side can be down in material but still have a positive evaluation due to other factors like piece activity, king safety, or pawn structure.
Limitations and things to keep in mind
Depth of Analysis: The deeper the analysis, the more accurate the evaluation. A quick evaluation might change with further analysis.
Human vs. Computer Play: Computers excel at tactical calculations, but humans often understand long-term strategic themes better. An evaluation that's slightly favorable for one side doesn't guarantee a win, especially in human play.
Changing Evaluations: As a game progresses and new moves are made, the evaluation can change rapidly. This is especially true in complex or tactical positions.
How to use evaluations to improve
Spotting Mistakes: A sudden change in the evaluation can point to a mistake or a brilliant move.
Comparing Your Analysis: After playing, compare your own assessment of a position to the computer's evaluation. It's a good way to identify areas for improvement.
Deep Understanding: Using Chess.com's analysis tools, you can get an in-depth understanding of why a particular move is favored by the engine.