Chess Opening Theory/1. e4/1...e5/2. Nf3/2...d6/3. d4/3...Nf6

Nimzowitsch variation Philidor defence 3...Nf6 · Nimzowitsch variation 3...Nf6 is the Nimzowitsch variation of the Philidor defence. Black leaves their e-pawn undefended to counterattack White's e-pawn instead. White's approaches are to either trade pawns or leave the central tension for now while they continue development. Trade pawns 1. e4 e5 2. Nf3 d6 3. d4 Nf6 4. dxe5 Nxe4 5. Qd5 Nc5 6. Bg5 Be7 7. exd6 Qxd6 8. Nc3 Qxd5 9. Nxd5 Bd6 10. O-O-O Rellstab variation, position after 5...Nc5 6. Bg5 Be7 7. exd6 Qxd6 8. Nc3 Qxd5 9. Nxd5 Bd6 10. O-O-O. Black cannot castle yet because of the threat of Be7!. 1 left If White chooses to trade pawns, 4. dxe5 Nxe4, the common club-level continuation, then 5. exd6 Bxd6 leads to equality for Black. A better try for White is 5. Qd5, the Rellstab variation. The queen threatens to recapture the knight and prevents d5 to defend it. Continuation is typically 5...Nc5 (saving the knight) 6. Bg5 Be7 (protecting the queen) 7. exd6 Qxd6 8. Nc3 Qxd5 9. Nxd5 (trading queens) Bd6 10. O-O-O+. White has a slight edge: the centre is opened and Black has some catching up to do in development. A tricky side line is 5. Bc4!?, preventing e5 and preparing a trap targeting the f7 square. If 5...dxe5?, before retaking White has the intermezzo 6. Bxf2+, winning a pawn. The black king cannot take back or it will drop the queen. 6...Ke7 7. Qxd8+ Kxd8 8. Nxe5++. White can also allow Black to trade into them. 4. Bc4, the Klein variation, is an uncommon reply where Black is allowed to take on e4. This move order gives White the option of a swift attack on f2. After 4...Nxe4 5. dxe5, White is prepared to meet 5...dxe5 6. Qxd8+ Kxd8 with 7. Nxe5, threatening to take on f7. If Black doesn't play 5...dxe5 White can meet most other moves with Bxf2+ Kxf2 Qd5+, forking the knight. 5...c6, preventing Qd5 and intending d5, is probably best. 4...exd4 usually transposes into the exchange Philidor after 5. Nxd4 Be7 6. Nc3. Defend the pawn 1. e4 e5 2. Nf3 d6 3. d4 Nf6 4. Nc3 Nbd7 5. Bc4 Be7 6. O-O O-O 7. Re1 c6 8. a4 b6 Lion variation, position after 5. Bc4 Be7 6. O-O O-O 7. Re1 c6 8. a4 b6. 1 left 4. Nc3 is the most common continuation in tournament games. This develops a piece and defends White's e4-pawn, so renews the threat of dxe5 dxe5 Qxd8+. Black would like to defend their e5-pawn. 4...Nc6!? however would run into 5. Bb5, pinning the knight, so Black plays 4...Nd7, known as the Lion variation. Typically both sides keep the central tension into the middlegame, White short castles and tries to break through on the queenside. Or, White can play 5. g4!?, the Shirov gambit: Black can take the pawn but then has to contend with the half-open g-file. Black still has the option of 4...exd4, transposing into an Exchange Philidor after 5. Nxd4. Defend one pawn while gambiting the other White has another way to defend the e4 pawn, and that's with 4. Ng5?!, the Locock variation. This looks like an eccentric move: White wastes time moving the same piece twice in the opening and drops their d4 pawn to boot, but it sets a couple of traps. 4...h6 to kick the knight away allows 5. dxe5, counterattacking the knight. Black should allow the trade and pick up the pawn, but a common mistake is 5...dxe5? 6. Qxd8+ Kxd8 7. Nxf7+, and White is up a rook. Black can take free pawn. 4...exd4 5. Bc4 threatens to win the pawn on f7. 5...d5 to interpose is sound, but after 6. exd5 Nxd5? is a mistake because the knight is now pinned to the f7 square. A continuation might be: 7. O-O Be7 (preparing to castle so defend f7) 8. Nxf7 (forking queen and rook) Kxf7 9. Qf3+ Bf6 10. Bxd5+ Kf8 11. Bxb7 Bxb7 12. Qxb7 +++. Theory table 0 4. dxe5 Nxe4 5. exd6?! Bxd6 Nimzowitsch variation 4. ... ... 5. Qd5 Nc5 6. Bg5 Be7 7. exd6 Qxd6 8. Nc3 Qxd5 9. Nxd5 Bd6 10. O-O-O Rellstab variation + 4. Nc3 Nbd7 5. Bc4 Be7 6. O-O O-O 7. Re1 c6 8. a4 b6 Lion variation + 4. ... exd4 5. Nxd4 - Exchange variation (transposition) References See also Philidor Defence External links Youtube: Solomon, Ruddell (TheChessGiant) https://www.youtube.com/watch?v=2WztzXJuLo0 Chess Openings: Learn to Play the Philidor Defense! 2021, The Chess Website https://www.youtube.com/watch?v=mAf-YuGPYMo Philidor Defense - Chess Openings 2012, Prem, Krishna https://www.youtube.com/watch?v=EKCMXf4g1HU Chess openings - Philidor Defence 2012, ChessPathways https://www.youtube.com/watch?v=0d5EU7rNkqs&t=6s The Philidor Defense 2019, Chess Openings for Beginners https://www.youtube.com/watch?v=4Y5sthOWJ4Q&t=12s Philidor Defense: General Information 2009, HangingPawns https://www.youtube.com/watch?v=Q4bp4qlRqGg Introduction to the Philidor Defense 2019 Marsh, Sean (ChessAble) https://www.chessable.com/blog/chess-opening-basics-the-philidor-defense/ Chess Opening Basics: The Philidor Defense 2021 ChessBase https://shop.chessbase.com/en/openings/philidor Philidor Defence 2023 ChessPathways https://chesspathways.com/chess-openings/kings-pawn-opening/philidor-defense/ PHILIDOR DEFENSE 2019 Chess Simplified https://simplifychess.com/philidor-defence/index.html Philidor Defence 2019