Chessy
Sodium Attack: Chenoboskion Variation – A Complete Beginner's Guide
Welcome to one of the wildest openings in chess. The Sodium Attack: Chenoboskion Variation begins with 1.Na3 g6 2.g4 — two moves that deliberately ignore every classical principle. You develop a knight to the edge of the board and push a flank pawn before touching a centre pawn. The engine rates this position at -1.14, a clear advantage for Black, so you are clearly worse here from the start. But don't let that scare you. Over 124 games in the Lichess database, White still wins 31.5% of the time, and Black's advantage is tricky to handle if they don't know the best replies. The drill below puts you in White's shoes — see if you can navigate the chaos better than the statistics suggest.
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Create a free account →The Main Idea: What Are You Fighting For?
When you play 1.Na3 g6 2.g4, you are not trying to out-theory your opponent. You are betting that the unusual structure will confuse them early. The knight on a3 looks misplaced, but it can reroute to c4 or b5, and the pawn on g4 eyes the f5 square while keeping options open for a quick h4-h5 advance. Black's most popular reply is Bg7 (82 games out of 124), which prepares to castle kingside. Against that, you can look to clamp down on the dark squares. The engine's preferred continuation for Black is Nc6, heading toward a sharp centre battle: Nc6 d4 d5 g5. In that line, your g4-g5 push tries to kick Black's knight and gain space. The key isn't playing 'correctly' — it's making your opponent prove they know how to refute you. Most club players don't, and that's where your 31.5% win rate comes from.
The Engine's Best Approach (and What It Tells You)
Stockfish's top recommendation for Black is 1.Na3 g6 2.g4 Nc6, planning d5 and a quick central occupation. After 3.d4 d5 4.g5, Black has a comfortable game, but you have forced them to play solid, principled moves. If you enjoy provocation — making your opponent find the narrow path — this opening is for you. From your perspective as White, the evaluation of -1.14 means you are worse, but the position is still rich with practical chances. Many players facing 1.Na3 immediately relax, and 2.g4 often feels disrespectful enough to tempt them into overpressing. Your job is to stay alert for their impatience and punish any overextension.
What the Statistics Reveal: Which Replies to Hope For
The numbers from 124 games tell a clear story: Black's best move is Nc6, but it is played less often than you might expect. Here is how White scores against the most common replies: - Bg7 (82 games): White wins 31.7% — your best chance comes against Black's most popular choice. - e6 (9 games): White wins only 22.2%, and the engine calls e6 an inaccuracy that loses about 0.8 pawns compared to Nc6. - d5 (6 games): White scores just 16.7% — Black immediately stakes a centre claim, and your position becomes tougher. - b6 (5 games): White scores 40.0% — your best percentage. b6 is labelled a mistake, losing ~1.4 pawns. - Nf6 (4 games): White wins 50.0% — even though it is classed as an inaccuracy. The lesson: if Black doesn't know the precise antidote, your chances jump significantly. Hope for b6 or Nf6; prepare for Bg7.
The Three Most Common Mistakes to Punish
The engine identifies three specific Black errors in this position. Knowing them helps you spot when your opponent goes wrong: - e6 (inaccuracy, loses ~0.8 pawns): Black blocks their queen's bishop and delays development. You can follow up with d4 and Bg2, seizing the centre while their pieces are passive. - b6 (mistake, loses ~1.4 pawns): A serious positional slip. Black weakens the c6 square and wastes a tempo. Punish it by playing d4, Nf3, and Bb5 — targeting the undefended kingside while Black's queenside is half-baked. - Nf6 (inaccuracy, loses ~0.6 pawns): Black develops a piece to a natural square, but it allows you to gain time with g5, kicking the knight to g8 or e4. After g5, you can follow with d4 and Bg2, building a broad centre while Black's knight runs. When you see any of these moves, seize the initiative — your opponent has handed you extra compensation for your unusual start.
Results across 124 Lichess games
| Most-played continuation | Games | White wins |
|---|---|---|
| Bg7 | 82 | 31.7% |
| e6 | 9 | 22.2% |
| d5 | 6 | 16.7% |
| b6 | 5 | 40.0% |
| Nf6 | 4 | 50.0% |
| f5 | 3 | 33.3% |
Frequently asked questions
Is the Sodium Attack: Chenoboskion Variation a good opening for beginners?
It is not a 'good' opening in the classical sense — the engine gives White a -1.14 disadvantage — but it can be a fun surprise weapon. It works best if your opponent panics against unusual moves. Beginners who want to learn sound opening principles should study 1.e4 or 1.d4 first. That said, the Chenoboskion Variation is excellent practice for handling chaotic, losing positions and making your opponent work for the win.
What is Black's best response to 1.Na3 g6 2.g4?
The engine's top move is 2...Nc6, planning d5 and a strong centre. The most popular move in practice, however, is 2...Bg7, appearing in 82 out of 124 games. Against Bg7, White scores 31.7%, which is actually slightly better than the overall average. So while Bg7 is natural, it is not the most punishing reply.
Why is the opening called the Sodium Attack?
The name 'Sodium Attack' comes from the chemical symbol for sodium (Na), which matches the notation for the knight moving to a3 (Na3). It is a tongue-in-cheek nickname for the ridiculous-looking 1.Na3. The 'Chenoboskion Variation' refers to the specific follow-up 1.Na3 g6 2.g4, named after the ancient Egyptian city of Chenoboskion. It is one of many bizarre lines in the A00 category of unorthodox openings.
Should I castle kingside in this opening?
Castling kingside can be risky because of your early g4 push — your king may be exposed on g1 if Black opens the centre. In many lines, it is safer to castle queenside or keep your king in the centre behind a solid pawn wall. Always evaluate based on where Black's pieces are aimed. If Black has played Bg7 and is ready to attack your kingside, consider castling long.