Anderssen's Opening
ECO A00beginner
1.a3 gives up any claim on the centre in exchange for information: Black must commit first, and White then plays a normal opening with the extra move already in place. That is not nothing — a3 is genuinely useful in several structures, where it prevents ...Bb4 or supports b4 — but it is a small return for handing Black a free hand on move one. Best understood not as an attempt at an advantage but as a way to reach an unfamiliar position where general understanding matters more than preparation.
Main line
1.a3 d5 2.Nc3 d4 3.Ne4 e5 4.e3
Diagram shows the position after 6 half-moves of the main line. On SpeakChess you can drill this line move by move — the trainer plays the other side and corrects you instantly, then spaced repetition schedules each variation so you review it right before you would forget it.
Win rates by rating
Results from real online games, measured after the line shown in each row. Most opening sites show one aggregate number — how an opening scores depends heavily on who is playing it.
| Rating | Games | White wins | Draws | Black wins | Position after |
|---|---|---|---|---|---|
| 400-600 | 56 | 37.5% | 8.9% | 53.6% | 1.a3 d5 |
| 600-800 | 294 | 40.1% | 6.5% | 53.4% | 1.a3 d5 |
| 800-1000 | 49 | 36.7% | 6.1% | 57.1% | 1.a3 d5 2.Nc3 d4 3.Ne4 |
| 1000-1200 | 25 | 32% | 4% | 64% | 1.a3 d5 2.Nc3 d4 |
| 1200-1400 | 56 | 26.8% | 3.6% | 69.6% | 1.a3 d5 2.Nc3 d4 3.Ne4 e5 4.e3 |
| 1400-1600 | 61 | 49.2% | 4.9% | 45.9% | 1.a3 d5 2.Nc3 d4 3.Ne4 e5 4.e3 |
| 1600-1800 | 34 | 50% | 2.9% | 47.1% | 1.a3 d5 2.Nc3 d4 3.Ne4 |
| 1800-2000 | 38 | 31.6% | 5.3% | 63.2% | 1.a3 d5 2.Nc3 d4 |
| 2000-2200 | 30 | 50% | 10% | 40% | 1.a3 d5 2.Nc3 d4 |
| 2200-2400 | 58 | 58.6% | 8.6% | 32.8% | 1.a3 d5 2.Nc3 d4 3.Ne4 |
Most played continuations (600-800 rating)
After 1.a3 d5:
- b3 — played 23.1% of the time (White wins 39.7%, draws 5.9%, Black wins 54.4%)
- b4 — played 20.1% of the time (White wins 37.3%, draws 3.4%, Black wins 59.3%)
- h3 — played 15.3% of the time (White wins 51.1%, draws 4.4%, Black wins 44.5%)
Frequently asked questions
Is 1.a3 a real opening or just a joke?
Real, if minor. Anderssen played it deliberately against Morphy, and the reversed-opening logic is coherent: many systems are perfectly good with an extra tempo, and a3 is a move those systems often want anyway. It does not claim an advantage, which is a different thing from being unsound.
How should Black respond?
Take the centre. 1...d5 or 1...e5 followed by natural development gives Black a comfortable game and effectively a tempo more than usual in an ordinary opening. There is nothing to avoid and no trap to sidestep — the correct punishment for a slow move is a fast, principled setup.
Why would anyone play it?
To get a game rather than a debate. Against a well-prepared opponent, reaching a position nobody has analysed can be worth more than the theoretical half-tempo it costs. That is a legitimate practical strategy, though it works better as an occasional choice than as a repertoire.
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