1.e4 Nf6 2.e5 Nd5 3.d4 d6 4.Nf3 Bg4 opens the Alekhine Defence: 1.e4 Nf6 2.e5... Bg4, ECO B05. Black pins the f3-knight before White can finish solidifying. The bishop trade for the knight is on the table, and so are doubled f-pawns if White isn't careful.
Strategic Overview
This is the Modern Variation main line, and 4...Bg4 is Black's most active and theoretically respected continuation. The point of the pin is to either force a structural concession or extract real value from the bishop-for-knight trade. White's usual responses are 5.Be2, breaking the pin and preparing castling, or 5.c4 to grab more space and use the queen on c2 or b3 ideas. In many lines Black voluntarily plays ...Bxf3 — often after gxf3 — accepting the bishop pair for White in return for fractured kingside pawns and a clear long-term target. The doubled f-pawns aren't terminal for White; the half-open g-file and bishop pair give real compensation, but Black has a clear plan and clear weaknesses to aim at. Black's typical follow-up involves ...e6, ...Nc6, ...Be7, and castling, with pressure building against e5 and d4. The middlegame becomes a battle between Black's better structure and White's bishop pair and space — both have something concrete to work with, which is why this line has been respected by everyone from Fischer to Carlsen. It's the soundest way for Black to play the Alekhine and avoid the worst of the cramped middlegames.
Key Ideas
A few ideas come up again and again in this opening:
- The pin on f3 is the whole point — Pinning the knight forces White to commit to a defense early. Either Be2 to break the pin, or accepting the trade ...Bxf3 with structural consequences. Black gets to dictate the character of the position.
- Doubled f-pawns are a long-term target — If White recaptures with gxf3, the structure is permanently compromised. Black gets a clear endgame plan and an obvious set of squares to aim at, balancing White's bishop pair.
- Black trades the bishop for structure — The light-squared bishop usually has no great future in Alekhine positions, so swapping it for the f3-knight is a good deal when it inflicts structural damage. Pieces for pawns work both ways.
- Pressure on e5 is constant — The e5-pawn is the central thing keeping White's position alive. Black builds up against it with ...e6, ...Nc6, and timely piece pressure, hoping to force exchanges or undermine the support chain.
History and Notable Players
It arises from the Alekhine Defence: 1.e4 Nf6 2.e5... 4.Nf3. On the White side, Lothar Vogt (18 games), Milan Matulovic (13 games), Gyula Sax (12 games) top the database. Notable Black exponents: Vladimir Bagirov (60 games), Jorge Szmetan (42 games), Lev O Alburt (41 games).
Performance Across Rating Levels
How well the Alekhine Defence: 1.e4 Nf6 2.e5... Bg4 works depends on what level you're playing at. At 1200 Elo, the opening shows up in 0.00% of games (15,732 samples). White scores 50.9%, Black 45.4%, draws 3.7%. Move up to 1800 Elo and the share shifts to 0.02%, with White winning 45.8% versus Black's 49.2%. At 2500, 0.11% of games go into this opening; draws sit at 9.2% — the line is well-mapped at this level. Positions also become less sharp as level rises (sharpness 0.96 → 0.91).
Time Control Patterns
The Alekhine Defence: 1.e4 Nf6 2.e5... Bg4 skews toward blitz chess. In bullet, it appears in 0.01% of games (310,683); White wins 49.8%. Blitz shows 0.02% adoption across 605,144 games, White scoring 47%. In rapid, the share rises to 0.01% — 85,349 games, White 46.7%. White's score swings 3.1pp across formats, so time control isn't just a stylistic choice here — it shifts the actual results.
Move Diversity and Theory Depth
What players actually play after the opening moves depends heavily on rating. At 1200 Elo, the top reply is Be2, played 34.7% of the time. There are 5 other moves seeing meaningful share, and 76.4% of games stick to established theory. Entropy: 2.60. By 2500, Be2 dominates at 78.8% of replies; only 3 viable alternatives remain and 93% of moves are theory. Entropy drops to 1.17. The narrowing is significant — strong players consolidate around a small set of best moves, while amateurs scatter across many plausible-looking options.
Historical Trends
Tracking the Alekhine Defence: 1.e4 Nf6 2.e5... Bg4 year over year shows a clear story. Adoption peaked in 2017 at 0.02% (26,032 games). By 2025 it sits at 0.01% — a 5% shift overall, leaving the line flat.
Common Mistakes
- Neglecting development — Extra pawn moves in the opening are tempting, especially when you "know the moves". Developing a piece each turn is the simple correction.
- Playing without a plan — Each Alekhine Defence: 1.e4 Nf6 2.e5... Bg4 middlegame demands a specific approach. Decide whether the position calls for attack, manoeuvre, or simplification before reaching for a move.
Practice on Chessiverse
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