Sodium Attack

The Sodium Attack starts with 1.Na3. The name ‘sodium’ is taken from the abbreviation of the metallic element ‘sodium’, as it’s used as ‘Na’ in the periodic table, and the annotation of the first move, ‘Na3′, looks similar. Officially, this opening is called the Durkin Opening, named after Robert T. Durkin (1923-2014) of New Jersey, who played it for decades. This guide covers what the Sodium Attack actually does on the board, what Black should play to refute it, the few traps White can hope for, and what kind of player should consider 1.Na3 in their own games. Spoiler: not many.

Sodium Attack is a rarely played flank opening at the master level due to its dubiousness. In contrast to the other gambits and dubious openings, it has a negative score for White players at the amateur level, which means it negatively affects White’s game even at the low level.

Winning percentages on both sides

Master level

Almost no master games exist with 1.Na3, it has been played by titled players in well under 500 classical games in the entire history of recorded chess.

Statistics from Lichess Amateur Games

Video Tutorial: How to Play the Sodium Attack

We are building a chess community on YouTube. Join us by subscribing and get access to all practical tips, strategies, and video lessons. Next stop: 200 subscribers.

Done with the quick video guide? Dive into the rest of the article to see move-by-move explanations and practical examples of the Sodium Attack.

Quick verdict

Is the Sodium Attack a good opening? Honestly, not in any objective sense. The knight is misplaced on a3 and has to move once again to become useful, gifting Black a tempo and easy central control. At master level it is unplayed. At amateur level (under 1800), Lichess opening explorer data shows White scoring 43%, one of the few first moves with such unsatisfied statistics. However, it does make sense if your opponent has never seen 1.Na3 before, because they will burn clock thinking. In a fast time control, against an unprepared opponent, that’s worth trying.

Key ideas: what is White actually trying to do?

1. Get the knight off a3. The knight cannot stay there. It will move to c4 (the most natural square, attacking e5-pawn), to c2 (a quieter retreat that supports a future d4), or in some lines to b5 (jumping into Black’s queenside). The knight needs at least one more move just to start participating.
2. Expand in the center with c4 or d4 once the knight has a path. Most reasonable plans for White involve playing 2.c4 quickly to control the center and give the a3-knight a route to c4-square if Black trades on c4.
3. Hope Black plays passively. The Sodium Attack only works against opponents who don’t know how to exploit White’s wasted tempo. If Black plays directly in the center, White is just down a move.

Sodium Attack’s Theory: Main Variations

1…d5 Variation: Black’s most principled response

Black’s strongest reply is the simple central pawn move 1…d5. This stops White’s e4 pushes immediately, claims the center, and forces White to figure out a plan with their misplaced a3-knight.

The most natural follow-ups for White are 2.c4 (preparing 3.Nxc4 if Black captures), 2.d4 (occupying the center despite the knight), or 2.b3 (preparing Bb2 to defend the knight on a3 indirectly).
There is one important tactical idea Black needs to know: White’s a3-knight can be captured by Black’s dark-squared bishop, creating doubled pawns on a-file. After 1…d5 2.Nf3 e6, the bishop on f8 is ready to take on a3 (3…Bxa3).

After 4.bxa3, White has the bishop pair as compensation, but the doubled a-pawns are a permanent weakness. Black is comfortably better in any endgame from this structure. White can try to make something of the long a1-h8 diagonal by putting their dark-squared bishop on b2, but at amateur level the structural damage usually outweighs the bishop pair.
This is why most White players prefer 2.b3 (so the c1-bishop can defend a3, keeping an eye on a1-h8 diagonal at the same time) or 2.c4 (which gives the knight a productive square). Both are covered below.

Line 1: 2.c4 — the main try

After 1…d5 2.c4, White’s idea is straightforward. If Black plays 2…dxc4, the a3-knight gets to recapture: 3.Nxc4. Now the knight is well placed, controlling e5 and d6, and the position resembles a King’s Indian Attack reversed. White will follow up with d3, g3, Bg2, and short castling. The pawn structure is fine, the only issue is that Black has had several easy developing moves.

This is the line White is hoping for, and unfortunately, it is also the line stronger Black players avoid. Anyone over 1200 Elo will recognize that capturing on c4 just helps White solve their knight problem. Better is 2…d4, locking the structure and entering a reversed Benoni. Black takes a big space advantage and White has to scramble for activity. A typical sequence:

Black has a beautiful setup: pawns on c5, d4, and e5 controlling the center, all the minor pieces developed, king safe. White has played quietly and will need a pawn break (a3-b4 or e3) to get any play at all. Black is comfortably better.

Line 2: 2.b3 and 3.Bb2

White’s other main try is 2.b3, preparing Bb2 to defend the knight indirectly.

After 1…d5 2.b3 e5 3.Bb2, Black has played the most challenging continuation — a strong central pawn duo and a bishop ready to come to d6 or c5. If Black plays 3…Bd6 to defend the e5-pawn, White has the resource 4.Nb5, suddenly attacking d6 and threatening to win the bishop pair:

To avoid Nb5 ideas, Black usually defends e5 with 3…Nc6 or 3…Nd7 instead. White then continues with e3, g3, Bg2, Nf3, and short castling, and eventually plays c4 to find a permanent home for the a3-knight. Even with all that, Black is still slightly better — the knight rerouting cost too much time.

1…e5: aiming for the e-pawn

Black’s other strong response is 1…e5, which has a different idea: don’t try to refute White’s setup, just take the center yourself. After 2.Nc4 (the only way to develop the misplaced knight), the knight attacks e5 and Black needs to defend it with 2…Nc6. Now White’s most aggressive try is 3.e4, hoping to lock in the central foothold and stop Black’s d5.

The problem: it doesn’t actually stop d5.

After 4.exd5 Qxd5, Black has an active queen on d5, fully developed pieces, and equal space. White is slightly worse — partly from the lost tempo with Na3-Nc4, partly from the open e-file with no pieces ready to exploit it. Most amateur Black players don’t play this line because it looks scary letting the queen out so early; that’s the only reason White survives at club level.

If both sides play forcing moves, the game can get sharp:

This line has been analyzed by 1.Na3 enthusiasts: Black’s queen gets harassed, White grabs the a8-rook with the knight on c7, but the knight gets trapped on a8 in return. The end position is roughly material-equal but Black’s coordination is better. Engines call it slightly worse for White.

3…Nf6: the calmer Black response

More common in amateur play than 3…d5 is the simple 3…Nf6, attacking the e4-pawn.

White defends with 4.d3, and now Black has a choice: 4…Bc5 (active piece development) or 4…d5 (transposing back to the d5 lines).

4…Bc5 leads to a tactical sequence White needs to know about. After 5.Nf3, Black has 5…Ng4!, threatening f2:

If White defends f2 with 6.Be3, Black trades a pair of pieces, then plays d5 to break open the center. White’s pawn structure is wrecked — doubled e-pawns, open f-file, weak dark squares. Black is significantly better. The improvement for White is 5.Be2 instead of 5.Nf3, sidestepping the Ng4 idea and preparing to develop the king’s knight more carefully.

3…f5: the Durkin Gambit

The most ambitious Black try is 3…f5, attacking e4 directly with a pawn. This line has its own name: the Durkin Gambit. Even though it’s Black sacrificing material, not White.

After 4.exf5 (though White can also decline with 4.d3), the game becomes sharp and tactical.

A typical line shows just how dangerous it is for White:

Black has to walk the king to e7 because 6…Nxh5 7.Qxh5+ wins the loose knight on f6. White then needs precise play to avoid being lost, typically 7.Ne3 d4 8.Nf1 Bxf5 9.Ng3, slowly bringing the c4-knight to safety:

White is still worse: Black’s king is exposed but the extra central pawn and active pieces compensate, but it’s still a fight.

The one real trap in the Sodium Attack

This trap shows up occasionally in club blitz games, after Black greedily grabs the c4-pawn:

After 5…Nbd7, the knight on e5 jumps to c6, attacking the queen on d8.

Pros and Cons of Sodium Attack

Should you play the Sodium Attack?

ChessDoctrine’s honest recommendation, by rating range:

• Under 1200 Elo: Don’t. You should be learning sound openings: 1.e4 or 1.d4. Building habits around an objectively bad opening will limit you later.
• 1200-1600 Elo: Maybe once or twice as a curiosity, in casual blitz. Not as a regular weapon.
• 1600-2000 Elo: As a surprise weapon in bullet, against opponents you’ve played before who you know like to play book moves. Don’t bring it to a tournament.
• Over 2000: You already know the answer. The opening is unsound and your opponents are too prepared for surprise value to matter.

Conclusion

The Sodium Attack is a bad chess opening with a great name. It violates opening principles, gives Black easy equality at minimum and an edge with accurate play, and exists in modern chess primarily as a curiosity. But if you’ve ever wanted to play 1.Na3 just to see what happens, to see if your opponent gives you the look, the lines in this article will keep you alive long enough to enjoy the moment.

Written by

Emre Sancakli, Chess Coach

Chess coach based in Turkey with chess.com ratings of 2410 blitz, 2380 rapid, and 2557 bullet — verifiable on his chess.com profile (mrsnckl). Has coached more than 100 students, from adult beginners to tournament players. Particularly enjoys teaching the Italian Game, French Defense, and King's Indian — openings that reward understanding ideas over memorizing lines.

Ask Question

FAQ’s

Is the Sodium Attack a good opening?

No. The knight is misplaced on a3 and has to move again, gifting Black a tempo. Chess engines evaluate the position after 1.Na3 at roughly -0.4 — small, but a meaningful giveaway from White’s first-move advantage. At master level it is essentially never seen. At club level its only real value is surprise: if your opponent has never faced it, they’ll burn clock figuring out a response.

Who invented the Sodium Attack?

The opening was popularized by American master Robert T. Durkin (1923-2014) of New Jersey, who used 1.Na3 throughout his career. The catchier name “Sodium Attack” was coined later by chess writer Eric Schiller in his 1998 book Unorthodox Chess Openings, riffing on the fact that “Na” is the chemistry symbol for sodium.

Has any grandmaster played the Sodium Attack?

There are no recorded games at classical time controls where a top-100 grandmaster has voluntarily played 1.Na3.

What is Black’s best response to 1.Na3?

Either 1…d5 or 1…e5. Both directly claim the center and force White to spend more time fixing the misplaced knight. Of the two, 1…d5 followed by 2…e6 (preparing Bxa3) is the most punishing if White isn’t careful, it can ruin White’s queenside pawn structure permanently.

Is the Sodium Attack the same as the Durkin Opening?

Yes, they’re the same opening (1.Na3) under two names. Older chess literature uses “Durkin Opening” or “Durkin’s Attack.”