Editing French Defence (section)

====Winawer Variation: 3...Bb4 <span class="anchor" id="Winawer Variation"></span>====<!-- This section is linked from [[Aron Nimzowitsch]] -->
This variation, named after [[Szymon Winawer]] and pioneered by Nimzowitsch and Botvinnik, is one of the main systems in the French, due chiefly to the latter's efforts in the 1940s, becoming the most often seen rejoinder to 3.Nc3, though in the 1980s, the Classical Variation with 3...Nf6 began a revival, and has since become more popular.

{{Chess diagram
| tright
|
|rd|nd|bd|qd|kd|  |nd|rd
|pd|pd|  |  |  |pd|pd|pd
|  |  |  |  |pd|  |  |
|  |  |pd|pd|pl|  |  |
|  |  |  |pl|  |  |  |
|pl|  |pl|  |  |  |  |
|  |  |pl|  |  |pl|pl|pl
|rl|  |bl|ql|kl|bl|nl|rl
| Winawer Variation after 3...Bb4 4.e5 c5 5.a3 Bxc3+ 6.bxc3
}}
3...Bb4 [[Pin (chess)|pins]] the knight on c3, forcing White to resolve the central tension. White normally clarifies the central situation for the moment with 4.e5, gaining space and hoping to show that Black's b4-bishop is misplaced. The main line then is: 4...c5 5.a3 Bxc3+ 6.bxc3, resulting in the diagrammed position.

While White has [[doubled pawns]] on the queenside, which form the basis for Black's counterplay, they can also help White since they strengthen his centre and give him a semi-open b-file. White has a spatial advantage on the kingside, where Black is even weaker than usual because he has traded off his {{chessgloss|dark-square bishop}}. Combined with the bishop pair, this gives White attacking chances, which he must attempt to use as the long-term features of this pawn structure favour Black.

In the diagrammed position, Black most frequently plays 6...Ne7 (The main alternative is 6...Qc7, which can simply [[Transposition (chess)|transpose]] to main lines after 7.Qg4 Ne7, but Black also has the option of 7.Qg4 f5 or ...f6. 6...Qa5 has recently become a popular alternative). Now White can exploit the absence of Black's dark-square bishop by playing 7.Qg4, giving Black two choices: he may sacrifice his kingside pawns with 7...Qc7 8.Qxg7 Rg8 9.Qxh7 cxd4 but destroy White's centre in return, the so-called "[[Poisoned Pawn Variation]]"; or he can play 7...0-0 8.Bd3 Nbc6, which avoids giving up material, but leaves the king on the flank where White is trying to attack. A more recent alternative is 7...Kf8, which tries to make use of the locked pawn centre (the king is safe from central attacks, and can run away from a kingside attack). Experts on the 7.Qg4 line include [[Judit Polgár]].

If the tactical complications of 7.Qg4 are not to White's taste, 7.Nf3 and 7.a4 are good positional alternatives, and 7.h4 is a more aggressive attempt:

7.Nf3 is a natural developing move, and White usually follows it up by developing the king's bishop to d3 or e2 (occasionally to b5) and castling kingside. This is called the Winawer Advance Variation. This line often continues 7...Bd7 8.Bd3 c4 9.Be2 Ba4 10.0-0 Qa5 11.Bd2 Nbc6 12.Ng5 h6 13.Nh3 0-0-0. Its assessment is unclear, but most likely Black would be considered "comfortable" here.

The purpose behind 7.a4 is threefold: it prepares Bc1–a3, taking advantage of the absence of Black's dark-square bishop. It also prevents Black from playing ...Qa5–a4 or ...Bd7–a4 attacking c2, and if Black plays ...b6 (followed by ...Ba6 to trade off the bad bishop), White may play a5 to attack the b6-pawn. World Champions [[Vasily Smyslov]] and [[Bobby Fischer]] both used this line with success.

White also has 7.h4, which has the ideas of either pushing this pawn to h6 to cause more dark-square weaknesses in the Black kingside (if Black meets h5 with ...h6, White can play g4–g5), or getting the rook into the game via Rh3–g3.

Black can also gain attacking chances in most lines: against 7.Qg4, Black will attack White's king in the centre; whereas against the other lines, Black can often gain an attack with ...0-0-0, normally combined with ...c4 to close the queenside, and then ...f6 to open up the kingside, where White's king often resides. If Black can accomplish this, White is often left without meaningful play, although ...c4 does permit White a4 followed by Ba3 if Black has not stopped this by placing a piece on a4 (for example, by Bd7–a4).

=====Sidelines=====
5th-move deviations for White include:
* 5.Qg4
* 5.dxc5
* 5.Nf3
* 5.Bd2

4th-move deviations for White include:
* 4.exd5 exd5, transposing to a line of the Exchange Variation, where White may aim to prove that Black's bishop on b4 is misplaced.
* 4.Ne2 (the Alekhine Gambit) 4...dxe4 5.a3 Be7 (5...Bxc3+ is necessary if Black wants to try to hold the pawn) 6.Nxe4 to prevent Black from doubling his pawns.
* 4.Bd3 defending e4.
* 4.a3 Bxc3+ 5.bxc3 dxe4 6.Qg4, another attempt to exploit Black's weakness on g7.
* 4.e5 c5 5.Bd2, again preventing the doubled pawns and making possible 6.Nb5, where the knight may hop into d6 or simply defend d4.
* 4.Bd2 (an old move sometimes played by [[Rashid Nezhmetdinov]], notably against [[Mikhail Tal]])

Deviations for Black include:
* 4...Ne7 although this move usually transposes to the main line.
* 4...b6 followed by ...Ba6, or 4...Qd7 with the idea of meeting 5.Qg4 with 5...f5. Theory currently prefers White's chances in both lines.
* Another popular way for Black to deviate is 4.e5 c5 5.a3 Ba5, the Armenian Variation, as its theory and practice have been much enriched by players from that country, the most notable of whom is [[Rafael Vaganian]]. Black maintains the pin on the knight, which White usually tries to break by playing 6.b4 cxb4 7.Qg4 or 7.Nb5 (usually 7.Nb5 bxa3+ 8.c3 Bc7 9.Bxa3 and White has the upper hand).