You finish a game on Chess.com, click "Analysis," and immediately see a wall of numbers: +0.56, -2.3, #7. The evaluation bar swings wildly and you have no idea what any of it means.
You're not alone. Chess engine evaluations confuse beginners and intermediate players constantly. This guide explains exactly what these numbers mean — and how to use them to actually improve.
What Is a Chess Engine Evaluation?
A chess engine evaluation is a numerical score that represents how advantageous a position is for one side. The score is expressed in pawns — or more precisely, in centipawns (hundredths of a pawn).
The sign tells you who's better:
- Positive (+) means White is better
- Negative (−) means Black is better
- 0.00 means the position is equal
What the Numbers Actually Mean
Here's a practical guide to evaluation ranges:
| Evaluation | Meaning |
|---|---|
| 0.00 to ±0.3 | Roughly equal. Both sides have good chances. |
| ±0.3 to ±0.8 | Slight advantage. A good player can press, but it's not decisive. |
| ±0.8 to ±1.5 | Clear advantage. One side is noticeably better — often a positional edge or an extra pawn. |
| ±1.5 to ±3.0 | Significant advantage. Usually a material advantage (pawn or more) plus activity. |
| ±3.0 and beyond | Winning advantage. The game should be decided with accurate play. |
| #N (e.g., #7) | Forced checkmate in N moves. The position is completely winning. |
What Is a Centipawn?
A centipawn is 1/100th of a pawn. Engines work in centipawns because they need precision that "pawns" can't provide.
So +1.5 means White is ahead by the equivalent of 1.5 pawns. +0.25 means White has a very slight edge worth about a quarter pawn — essentially equal, but marginally better.
Standard Piece Values (in Pawns)
Engines use roughly these piece values as their baseline:
| Piece | Approximate Value |
|---|---|
| Pawn | 1.0 |
| Knight | 3.0–3.2 |
| Bishop | 3.2–3.5 |
| Rook | 5.0 |
| Queen | 9.0–9.5 |
These aren't fixed — modern engines adjust values dynamically based on the position. A knight on an outpost might be worth more than a bishop trapped behind its own pawns.
The Evaluation Bar
The evaluation bar is a visual representation of the engine score. The more white it shows, the better for White. The more black, the better for Black.
Key insight: The bar is most useful for tracking changes in evaluation rather than absolute values. A sudden swing from +0.3 to -1.8 tells you something important just happened — look at that move.
What About Inaccuracy, Mistake, and Blunder?
Chess.com and Lichess categorize moves by how much they change the evaluation:
| Category | Evaluation Loss |
|---|---|
| Excellent / Best | 0–0.10 loss |
| Good | 0.10–0.25 loss |
| Inaccuracy | 0.25–0.50 loss |
| Mistake | 0.50–1.50 loss |
| Blunder | 1.50+ loss |
A blunder typically means you've given up a significant material or positional advantage — often a hanging piece, a missed tactic, or a losing position.
Why You Shouldn't Stare at the Eval Bar During Play
The eval bar is an excellent study tool, but watching it during your games can actually hurt your improvement. It trains you to react to the number rather than understand the position.
Instead, try to:
- Evaluate the position yourself before moving
- Make your move, then check what the engine says
- If you were wrong, understand why before moving on
Seeing Engine Suggestions in Real Time
One of the best ways to internalize engine evaluations is to watch Stockfish arrows appear in the positions you're actually playing — not hours later in a review session. ChessSolve overlays real-time Stockfish analysis arrows directly on your board as you play on Chess.com or Lichess.
This turns abstract evaluation numbers into concrete visual moves. Over time, you start to see the best square before the engine shows it — which is the whole point.
Engine evaluations are a tool, not the point of chess. Use them to understand what went wrong in your games and why certain moves are better — not to judge yourself harshly for every centipawn lost. Even grandmasters play moves the engine doesn't like. The goal is to understand chess better with each game you study.