What Are Chess Databases?
A chess database is exactly what it sounds like — a digital library of chess games stored in PGN (Portable Game Notation) format. Think of it as a searchable archive where every master-level game ever recorded lives alongside metadata: players, ratings, ECO codes, tournament names, and dates.
The scale of modern chess databases is staggering. 365Chess, one of the most popular free database platforms, records over 1.9 million games for the single move 1.e4 alone. Its Opening Explorer lets you "browse our entire chess database move by move, obtaining statistics about the results of each possible continuation." Chessify, a cloud analysis platform, goes further by integrating three major databases — Mega DB, ICCF DB, and Lichess DB — directly into its analysis interface.
Most platforms let you search by player name, opening variation, position (via FEN), or tournament. Need to know how Magnus Carlsen has played against the Najdorf as White this year? That is a database query, and it takes seconds.
Opening Explorers: Statistics in Action
If databases are the raw library, opening explorers are the analytical index. An opening explorer takes those millions of games and builds a statistical tree: for every legal move in a given position, it shows you how many games reached that point, the winning percentages for White and Black, the draw rate, the last year the move was played at the master level, and an engine evaluation.
The 365Chess Opening Explorer gives you all of this in one view. The numbers at the top of the tree are revealing:
| Move | Games | White / Draw / Black | Engine Eval |
|---|---|---|---|
| 1.e4 | 1,920,957 | 37.9% / 30.7% / 31.4% | +0.34 (depth 49) |
| 1.d4 | 1,276,829 | 37.5% / 34.2% / 28.2% | +0.26 (depth 50) |
| 1.Nf3 | 340,302 | 37.2% / 37.0% / 25.8% | +0.25 (depth 48) |
| 1.c4 | 269,716 | 37.8% / 34.6% / 27.6% | +0.22 (depth 46) |
Note that every first move that has been played at least a few hundred times yields a White win rate between 37% and 38% — except 1.f4 (34.9%) and the truly rare moves. The real story is in the draw rates: 1.Nf3 draws 37% of the time, the highest among popular first moves, hinting at the quieter, positional battles it tends to produce.
Shredder Chess, the long-running engine developed by Stefan Meyer-Kahlen, also offers a free online opening database. According to Shredder Chess, it "contains about 26 million moves from the latest chess grandmaster games and gives you a survey of what has ever been played by strong human chess players." Shredder Chess also offers a separate Endgame Database tool alongside its opening resource.
Chess.com and Lichess both include opening explorer functionality within their analysis boards — Chess.com calls it the "Explore" tab, while Lichess has a dedicated "Openings" tool under its Tools section. Both let you browse move trees with win/draw/loss statistics drawn from their respective game collections.
Endgame Tablebases: Mathematical Perfection
Chess engines are powerful, but they are approximations — they search and evaluate. Endgame tablebases are different. A tablebase is an exhaustive, retro-analytical database that stores the perfect outcome for every possible position with a limited number of pieces. When a tablebase says the position is a win in 17 moves, it is not guessing. It knows.
The Syzygy tablebase format, which supports the DTZ (Distance to Zero) metric, is the modern standard. DTZ tells you how many moves until a capture or pawn push that guarantees a win or draw under perfect play. Both 365Chess (on its analysis board) and Chessify (in its engine settings) integrate Syzygy tablebases directly — they activate automatically when the position qualifies.
In practice, tablebases are a specialized tool. Unless you are grinding out a rook endgame against a strong opponent or checking whether that tricky king-and-pawn race is actually winning, you will rarely need them. But when you do, nothing else compares.
Engine Analysis Tools: Free vs. Paid
Free Browser-Based Analysis
Lichess offers one of the strongest free analysis experiences anywhere. Its analysis board runs "SF 18 dev 85MB NNUE" — Stockfish 18 development version with an Efficiently Updatable Neural Network — entirely in your local browser. No limits, no signup required. It also supports multiple chess variants (Crazyhouse, Chess960, King of the Hill, Three-Check, and more) for those who enjoy exploring beyond standard chess.
Chessigma's Next Move Calculator takes a different approach. It runs Stockfish 17 via WebAssembly directly in your browser. "No data is sent to any server," the platform emphasises. It is free, unlimited, requires no account, and analyses positions to depth 20+ depending on your device's processing power.
365Chess's analysis board is powered by Stockfish 18, described as "a world-class chess engine, offering detailed insights into your positions and games." It shows engine evaluation with depth (for example, +0.42 at depth 17/60), multiple variation lines, and supports both FEN and PGN import. Free users can save up to 10 analyses.
Paid and Cloud-Based Options
Chessify stands apart as a cloud analysis platform. Instead of running the engine on your computer, it runs Stockfish 18, Stockfish 17.1, CorChess, Lc0 0.32.1 (on a dedicated GPU server), Berserk 13, Caissa 1.22, Crystal 9, Patricia 4, Viridithas, ShashChess 38, Koivisto 9.2, RubiChess, AsmFish, and Sugar AI — fourteen engines in total.
The free plan runs on shared 16-thread servers at approximately 1 MN/s (mega-nodes per second), which Chessify notes varies by engine and position — "lower in openings, higher in endgames." Dedicated plans offer 320 or 704 threads for serious analysis work. Lc0 can use multiple neural network architectures, from the faster J104.1-30 (~220 kN/s) to the deeper BT4-1024×15 (~4 kN/s).
Chess.com's analysis board offers tabs for Set Up Position, Explore (opening explorer), Game Search, and Game Collections. However, according to Chessigma's comparison page, Chess.com free users are limited to one game analysis per day, with full analysis requiring a premium subscription.
Tools Comparison Table
| Tool | Type | Free Tier | Engine | Key Limitation |
|---|---|---|---|---|
| 365Chess | Analysis Board + Opening Explorer | Stockfish 18 analysis, opening stats, save up to 10 analyses | Stockfish 18 | 10-save limit for free users |
| Chess.com | Analysis Board + Calculator | Basic analysis; free analysis cap | Stockfish | Free analysis cap per day |
| Lichess | Analysis Board + Openings | Full analysis, unlimited, multi-variant | SF 18 dev (browser) | Analysis speed depends on your hardware |
| Chessigma | Next Move Calculator | Free, no signup, unlimited | Stockfish 17 (WebAssembly) | Depth limited by device (depth 20+) |
| Shredder Chess | Opening Database | Free online database | N/A (statistical only) | No built-in engine analysis |
| Chessify | Cloud Analysis | Shared 16-thread, ~1 MN/s | 14+ engines (SF 18, Lc0 GPU) | Speed drops on opening positions |
Each tool serves a different purpose. Think of 365Chess and Shredder as your reference library, Lichess and Chessigma as your practice room, and Chessify as the analysis laboratory you upgrade to when you need more horsepower.
Fair-Play Boundaries: When Not to Use Tools
This is the most important section of this article.
The Chessigma FAQ draws a clean ethical line: "Using an engine during a rated game is cheating. Using one to study positions, analyze completed games, or learn from your mistakes is standard chess improvement practice."
Chessigma also notes that "at depth 20+, Stockfish plays at a level far beyond any human. It is the gold standard for chess analysis and has won the Top Chess Engine Championship multiple times."
The implication is straightforward. These tools are astonishingly strong — too strong to be anywhere near a live game. The fairness principle is simple: if the game clock is running and the result affects your rating, you do not consult any external analysis. This applies to databases, opening explorers, tablebases, and engines alike.
For correspondence (daily) chess, policies differ by platform. Lichess explicitly allows opening books in daily games. Chess.com's policy may differ. If you play daily chess, check the platform's fair-play rules before consulting any tool. When in doubt, err on the side of studying only after the game ends.
For beginners: start with free tools. Lichess analysis board and Chessigma's Next Move Calculator are both free, unlimited, and run entirely in your browser. You do not need to spend money to review your games and improve. Master-level analysis is available to anyone with an internet connection.
Choosing the Right Tool for Your Level
Match the tool to your goal:
- For opening research — use 365Chess Opening Explorer or Shredder Chess. Both give you statistical depth based on real master games.
- For game review — Lichess analysis board (free SF 18 dev) or Chessigma (free, no account) are excellent starting points.
- For deep multi-engine analysis — Chessify if you want to compare how Stockfish, Lc0, and Berserk evaluate the same position.
- For endgame verification — stick with tablebase-integrated tools like 365Chess or Chessify. When a position has seven or fewer pieces, the tablebase result is definitive.
As you progress, you can scale up. Beginners benefit most from the free browser tools. Intermediate players graduate to opening explorer statistics to build and refine their repertoires. Advanced players investing serious time into preparation may find cloud services like Chessify worth the cost.
Conclusion
Chess infrastructure tools fall into three clear categories: databases store the games, opening explorers analyse them statistically, and tablebases solve them perfectly. Free options from Lichess, Chessigma, and 365Chess cover most needs for most players, while cloud platforms like Chessify provide industrial-strength analysis for those who need it.
The key takeaway is simple: you do not need to pay to improve. The free tools covered here are enough to take any player from beginner to advanced. What matters is how you use them — study your games, learn your openings, verify your endgames, and keep the engine off during live play.
Frequently Asked Questions
What is the difference between a chess database and an opening explorer?
A database stores raw game files in PGN format. An opening explorer aggregates those games into a statistical tree showing win rates, draw rates, and engine evaluation for each legal move at every position.
Are chess tablebases better than chess engines?
For positions with seven or fewer pieces, tablebases are perfect — they know the forced outcome. Engines are approximations. For positions with more pieces, engines are the only option.
Is it cheating to use a chess opening explorer?
Using any engine or analytical tool during a live rated game is cheating. Using an opening explorer to study openings between games or review completed games is standard practice. For daily (correspondence) chess, policies vary by platform.
Which free chess analysis tool is best?
Lichess (Stockfish 18 dev, unlimited, no signup) and Chessigma (Stockfish 17 via WebAssembly, no account required) are the strongest free options. 365Chess offers excellent opening statistics with no cost for basic use.
What is the Syzygy tablebase and DTZ?
Syzygy is the most widely used endgame tablebase format. DTZ (Distance to Zero) tells you how many moves until a capture or pawn push that guarantees a win or draw under perfect play. Both 365Chess and Chessify integrate Syzygy tablebases directly.
Want more chess strategy guides and analysis resources? Visit the Togyzkumalak blog for in-depth articles on openings, tactics, and everything between.
Sources:
- 365Chess — Analysis Board (https://www.365chess.com/analysis_board.php)
- 365Chess — Opening Explorer (https://www.365chess.com/opening.php)
- Chessigma — Next Move Calculator (https://www.chessigma.com/tools/next-move)
- Shredder Chess — Opening Database (https://www.shredderchess.com/online/opening-database.html)
- Chessify — Cloud Analysis (https://chessify.me/analysis)
- Lichess — Analysis Board (https://lichess.org/analysis)
- Chess.com — Analysis Board (https://www.chess.com/analysis)
