Is chess.koz.tv free to use?

Yes, chess.koz.tv is completely free. You can analyze unlimited games from Chess.com, Lichess, or upload PGN files without any subscription or payment.

What chess platforms are supported?

chess.koz.tv supports Chess.com, Lichess, and custom PGN file uploads. You can import games from any of these sources for analysis.

How does the chess analysis work?

We use Stockfish 17, the strongest open-source chess engine. Analysis runs on our servers at depth 15+, with many positions pre-analyzed at depth 20+ from the Lichess database. We provide centipawn evaluations, move classifications, accuracy ratings, and opening detection.

Can I analyze multiple games at once?

Yes, you can import and analyze multiple games at once. We also offer batch analysis features to identify patterns across your recent games.

Why does Chess.com show different accuracy than Lichess?

Chess.com and Lichess use different accuracy formulas. Chess.com's CAPS (Computer Aggregated Precision Score) and Lichess's win probability method produce different numbers. chess.koz.tv uses the Lichess formula for accuracy calculations.

Chess Accuracy Calculator - Check Your Game Accuracy Free

What is Chess Accuracy?

Chess accuracy is a percentage that measures how closely your moves match the computer's recommended best moves. A higher accuracy means you played more like a perfect chess engine, while lower accuracy indicates more suboptimal decisions.

The accuracy calculation works by analyzing the centipawn loss of each move — how much evaluation you "lost" compared to the best move. This centipawn loss is converted to win probability, then averaged across all your moves to produce the final percentage.

Accuracy is useful for tracking improvement over time, comparing performance across games, and identifying where you tend to make the most costly mistakes.

What is a Good Chess Accuracy?

Your expected accuracy depends heavily on your rating level. Here's what to aim for:

Rating Range	Expected Accuracy	Description
Under 800	50-60%	Beginner — many blunders expected
800-1200	60-70%	Novice — fewer major blunders
1200-1600	70-80%	Intermediate — consistent play
1600-2000	80-88%	Advanced — solid technique
2000-2400	85-92%	Expert/Master — high precision
2400+	90-98%	Grandmaster — near-perfect play

Note: Accuracy can vary significantly by game. Time control, complexity of positions, and whether you're winning or defending all affect your accuracy score.

How We Calculate Accuracy

chess.koz.tv uses the Lichess accuracy formula, which is based on win probability conversion:

Each position is evaluated by Stockfish 17 to get a centipawn score
Your move's evaluation is compared to the best move's evaluation
The centipawn difference is converted to win probability loss
All moves are averaged to produce your accuracy percentage

This method is more nuanced than simply counting blunders, as it considers the magnitude of each mistake and weights critical positions appropriately.

Why Does My Accuracy Differ from Chess.com?

If you've used Chess.com's game review, you may notice different accuracy numbers. This is because Chess.com uses their proprietary CAPS (Computer Aggregated Precision Score) formula, while we use the Lichess win probability method.

Neither is "wrong" — they're just different mathematical approaches to measuring move quality. Generally:

Chess.com accuracy often shows slightly higher numbers
Lichess/chess.koz.tv accuracy is more sensitive to small inaccuracies
Both correlate strongly with playing strength

The important thing is consistency: track your accuracy over time using the same platform to measure improvement.

How to Improve Your Chess Accuracy

Analyze Your Games

Review every game to understand where you went wrong. Focus on moves with high centipawn loss.

Solve Tactics Daily

Most accuracy losses come from missed tactics. 15-30 minutes of puzzles daily builds pattern recognition.

Play Longer Time Controls

Give yourself time to think. Accuracy in 10-minute games is typically 10-15% higher than bullet.

Use Batch Analysis

Analyze multiple games to find recurring mistake patterns and problematic positions.

Frequently Asked Questions

What is a good chess accuracy percentage?▼

A good accuracy depends on your rating. Beginners typically score 55-65%, intermediate players 70-80%, advanced players 80-90%, and masters 90%+. Focus on improving your personal average over time.

Is 90% accuracy good in chess?▼

Yes, 90% accuracy is excellent — this is master-level play. If you consistently achieve 90%+ accuracy, you're playing at a very high level with minimal mistakes.

Why is my accuracy lower in fast games?▼

Time pressure causes more mistakes. In bullet (1-2 minutes), even grandmasters see accuracy drops of 10-20% compared to classical games. This is normal.

Is the accuracy calculator free?▼

Yes! chess.koz.tv provides unlimited free accuracy calculations. No signup required — just import your games and see your accuracy for every game.

Check Your Chess Accuracy Now

Import your games from Chess.com, Lichess, or upload PGN — free analysis with no signup

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