|Moves||1.e4 e5 2.Nf3 d6|
|Named after||François-André Danican Philidor|
The Philidor Defence is a chess opening characterised by the moves:
The opening is named after the famous 18th-century player François-André Danican Philidor, who advocated it as an alternative to the common 2...Nc6. His original idea was to challenge White's centre by the pawn thrust f7-f5.
Today, the Philidor is known as a solid but passive choice for Black, and is seldom seen in top-level play except as an alternative to the heavily analysed openings that can ensue after the normal 2...Nc6.
The ECO code for Philidor Defence is C41.
The Philidor occurred in one of the most famous games ever played, the "Opera Box game" played in 1858 between the American chess master Paul Morphy and two strong amateurs, the German noble Duke Karl of Brunswick and the French aristocrat Count Isouard. The game continued 3.d4 Bg4, a deviation from modern standard lines.
As of 2004, there are no top players who employ the Philidor with any regularity, although Étienne Bacrot and Liviu-Dieter Nisipeanu have occasionally experimented with it. Its popularity in master play has increased slightly over the last twenty years, however.
With 3.d4 White immediately challenges Black in the centre. In this position, Black has several options.
The most common Black response is 3...exd4 which relieves the central tension, although it gives up the centre. After 4. Nxd4 Nf6 5. Nc3, Black normally continues ...Be7 and ...0-0 (the Antoshin Variation) and achieves a strong defensive position.
Instead of 4.Nxd4, White can also play 4. Qxd4, as Paul Morphy favoured, intending 4... Nc6 5. Bb5 Bd7 6. Bxc6 Bxc6 7. Nc3 Nf6 8. Bg5 followed by 0-0-0. This line was played in many 19th-century games.
The other main option for Black is to maintain the central tension and adopt a setup with ...Nd7, ...Be7, and ...c6. This plan is named the Hanham Variation (after the American chess master James Moore Hanham) and was favoured by Aron Nimzowitsch. A common line is: 3... Nf6 4. Nc3 Nbd7 5. Bc4 Be7 6. 0-0 (6.Ng5 is an interesting alternative: after 6...0-0 7.Bxf7+ Rxf7 8.Ne6 Qe8 9.Nxc7 Qd8 10.Nxa8, White is material up, but Black can develop a strong initiative after, for example, 10...b5 11.Nxb5 Qa5+) 6... 0-0 7. a4 (to prevent ...b5) 7... c6 (see diagram).
Grandmaster Larry Kaufman, in his book The Chess Advantage in Black and White, notes that the Hanham Variation aims to maintain Black's pawn on e5, analogously to closed lines of the Ruy Lopez, and opines that "it would be quite popular and on a par with the major defenses to 1.e4, except for the annoying detail that Black can't actually reach the Hanham position by force."
As an alternative to 4.Nc3 in response to Black's 3...Nf6, according to both Kaufman and Grandmaster Christian Bauer, White retains some advantage with: 4. dxe5! Nxe4 5. Qd5! Nc5 6. Bg5 Be7 7. exd6 Qxd6 8. Nc3.
Black sometimes tries 3... Nd7 intending 4.Nc3 Ngf6, reaching the Hanham Variation. But then 4. Bc4! is awkward for Black to meet, since 4...Ngf6 loses to 5.Ng5, and 4...Be7 loses a pawn to 5.dxe5 Nxe5 (5...dxe5?? 6.Qd5! wins) 6.Nxe5 dxe5 7.Qh5! So 4... c6 is best for Black, but leaves White with the advantage of the bishop pair after 5. 0-0 Be7 6. dxe5 dxe5 (6...Nxe5 loses a pawn to 7.Nxe5 dxe5 8.Qh5) 7. Ng5! Bxg5 8. Qh5! Qe7 and now 9.Bxg5 or 9.Qxg5.
In recent years, Black has experimented with other move orders in an attempt to reach the Hanham Variation while avoiding 3...Nf6 4.dxe5! and 3...Nd7 4.Bc4!
A more aggressive approach for Black after 3.d4 is 3...f5!? (see diagram), now called the Philidor Counter Gambit, a move which Philidor himself recommended. According to Philidor, the move 3...f5 can also be played after 3.Bc4, which can lead to unique positions such as 3.Bc4 f5 4.d3 c6, possibly followed by f5-f4, b7-b5, a7-a5, and even g7-g5 and h7-h5, when all Black pawns have moved before any piece.
In the 19th century, 3...f5 was also played by Paul Morphy. The move can lead to more open positions than the other lines, but is often considered dubious. Others maintain that 3...f5 is a valid idea. Grandmaster Tony Kosten treats the move with respect in his monograph on the opening. The move was also played by David Bronstein and by Teimour Radjabov.
The main alternatives after 3.d4 f5 are:
All of these lead to a small advantage for White with correct play.
Inferior is 3...Bg4?!, in light of 4. dxe5 Bxf3 (alternatively, Black can gambit a pawn with 4...Nd7?!, known as the Duke of Brunswick Gambit) 5. Qxf3 dxe5 6. Bc4 giving White the advantage of the bishop pair in an open position. (Now the "natural" 6...Nf6? allows White to win a pawn with 7.Qb3. This was played in the famous "Opera Box game", when Paul Morphy as White declined to win the pawn but retained a strong initiative after 7...Qe7 8.Nc3.)
An alternative approach for White is to play 3.Bc4, and either delay d2-d4, or forgo it altogether and instead play d2-d3. The move 3.Bc4 is also White's route to an attempted Légal Trap. The continuation 3...Nc6 brings about the Semi-Italian Opening.