Sodium Attack

The Sodium Attack is the opening move 1. Na3, also called the Durkin Opening. Eric Schiller gave it its chemical name because Na is the symbol for sodium. The other name comes from Robert Durkin of New Jersey. The Oxford Companion to Chess notes that he used the move in both over-the-board and correspondence play, and that almost no one else took it up.

The knight on a3 covers only b5 and c4. It exerts no pressure on the central squares and blocks nothing Black wants to do, so the move is close to a tempo pass that lets Black pick a setup first. Black usually accepts the invitation to occupy the center. 1...e5 is the most common reply, followed by 1...d5 and, less often, 1...e6. The engine gives Black a slight edge after the first move, and Black wins more often than White in the database games.

After 1...e5, the knight's natural route is 2. Nc4, where it attacks the e5-pawn and gives the rim development a purpose. The Durkin Gambit continues 2...Nc6 3. e4 f5. White has a pawn on e4 and Black answers by hitting it with the f-pawn. This opens the position early and turns the game into an open, tactical fight rather than a slow maneuvering one. The Celadon Variation takes a different route with 2. d3 Bxa3 3. bxa3. Black gives up the dark-squared bishop at once to double White's a-pawns. In return, White gets the bishop pair and a half-open b-file. After 3...d5 4. e3 c5 5. Rb1, the rook goes straight to that file to bear down on b7, while Black has a broad pawn center and better structure. The Chenoboskion Variation, 1...g6 2. g4, answers Black's kingside fianchetto with an early flank pawn thrust and is even more eccentric.

The move remains a rarity. It sits in the lower-middle range of named openings by the number of games reaching its position, and it has almost no established theory. In practice it is a surprise choice, mostly in fast online games, where the aim is to take the opponent out of familiar territory rather than to gain anything from the opening itself.