The Poisoned Pawn Variation is one of the main branches of the 6.Bg5 Najdorf. It is a highly provocative attempt by Black to get away with stealing White’s b-pawn. Ironically each time a player now tries to get away with winning the opponent’s b-pawn with one’s queen in any opening, it is considered a poisoned pawn. Yet somehow White has not been able to refute the Poisoned Pawn Variation.
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The starting position arises after 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Bg5 e6 7.f4 Qb6 8.Qd2. We are now looking at the Poisoned Pawn Variation from the Black side and what it takes to survive White’s active compensation for the pawn.

8…Qxb2 is the consistent continuation to 7…Qb6. Black is now up a pawn, but the drawbacks appear to be overwhelming. Black delays piece development, misplaces his queen, opens the b-file for White’s rook and allows White a promising attack against his uncastled king.

9.Rb1 is the main line, but White has also tried the more patient 9.Nb3. The main idea of this knight move is to make it hard for Black’s queen to get back into the game. Black should then choose 9…Nc6 or 9…Qa3 with a satisfactory game.
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White continues to gain time and now has five pieces in play compared to Black’s two. Black will need to play very accurately to get out of the opening alive.

9…Qa3 is the only option worth considering to save the attacked queen.

10.Be2 became one of the main weapons for White in the 1980s and is still played quite often. The idea is quite straight forward. White wants to castle kingside and after getting all pieces involved in the attack, break the position open with either e4-e5 or f4-f5, depending on what Black will do. More direct means to refute Black’s pawn robbery are 10.Bxf6 10.e5 and 10.f5. While each of these lines is quite tricky and requires Black to be familiar with the main ideas, they do not present a greater danger than the text move.
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Black needs to catch up in development now.

10…e5? weakens the d5-square too much. After 11.Bxf6 gxf6 12.Nf3, White has a big advantage.

10…Be7 is the most solid move. Black now has the option to recapture the f6-knight with the bishop and can also castle kingside if needed. The main alternatives are 10…Nbd7 which may transpose later on or the riskier 10…b5.

11.0-0 completes White’s development while Black is just getting started in this department. Now White will usually try to open up the road to Black’s king at all cost.
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Black has tried many continuations at this point.

11…0-0 is too risky at this point. After 12.e5 dxe5 13.fxe5 Nfd7 14.Ne4!?, White obtains a promising kingside attack. There is no rush to castle kingside yet.

11…Qa5 tries to stop White from playing e4-e5 and also gives Black the retreat diagonal a5-d8. But after 12.f5 e5 13.Nb3, White has the edge.

11…Qc5 gets the queen centralized with gain of time, eyes the critical e5-square and gives it the option to retreat to the ideal Sicilian c7-square if need be. Moving the queen for the fourth time appears very risky, yet White has not been able to refute this line of play. Less reliable choices are a) 11…0-0?! 12.e5; b) 11…Nc6 12.Nxc6 bxc6 13.e5 and c) 11…Qa5 12.f5 e5 13.Nb3, all giving White a promising position. 
The most popular choice, 11…Nbd7, is usually met by the pawn sacrifice 12.e5 dxe5 13.fxe5 Nxe5 14.Bxf6, and Black has a difficult defense ahead. The most solid move may be 11…h6, when 12.Bh4 Nbd7 leads to a complex position.

12.Kh1 moves the king out of the dangerous a7-g1 diagonal and thus unpins the knight on d4. Black had to foresee that 12.Na4 Qc7 13.Nb6 Ra7 is less powerful for White than it looks, e.g., 14.Qe3 d5! and White has to watch the counter play on the a7-g1 diagonal. If White then tried 15.e5, Black gets fine compensation for the exchange after 15…Ne4 16.Nxc8 Qxc8 17.Bxe7 Kxe7 18.Nf5+ exf5 19.Qxa7 Nc5!
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Now Black is only a few moves away from completing his development. You will need to look at how White may want to penetrate.

After 12…Nc6?!, White obtains a good position with 13.Nxc6 Qxc6 14.Bf3. If 13…bxc6, then 14.Na4 and 15.Nb6 wins material.

12…Nfd7? covers the important b6-square and also eyes the e5-square once again. But after 13.Bxe7 Kxe7 14.Bf3, Black will find it hard to come up with a good plan.

12…Nbd7 gets the knight to its ideal square. Now Black controls the important e5-square with another piece and makes it harder for White to sacrifice the e-pawn with e4-e5 under favorable circumstances. The knight on d7 also protects the important b6-square and thus took the sting out of White’s planned Na4-b6 maneuver.

White changes plans with 13.f5 now that the e4- e5 was no longer promising. With this pawn advance, White attacks the e6- pawn another time. Other possible continuations include 13.Rf3 b5!? or 14.Nb3 Qc7 with a double edged position.
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You will need to deal with White’s threat first.

13…e5 takes the pressure of the pawn on e6 and keeps the position closed. Even though White now has control over the important d5-square, this is Black’s best move. Instead 13…Nb6 looks very shaky, since only the queen protects this frail horse. White could then get a strong attack with 14.fxe6 fxe6 15.Bxg5 Bxf6 (15…gxf6 16.Bh5+ is good for White) 16.Bh5+!

14.Ne6 throws a piece into the sacrificial fire in order to disrupt Black’s development, open some lines to Black’s king and try to prevent Black’s king from ever castling. Black’s position was solid after both 14.Nf3 and 14.Nb3.
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White doesn’t give you too many choices here.

14…fxe6 is forced as the knight is too dominating on e6. If you moved the attacked queen instead, White’s knight could just win the g7-pawn with check and obtain a winning advantage.

15…Nb6!? is the most ambitious way to fight for a win for Black. The main alternative 15…Nf8 leads to unclear play after 16.Bxf6 gxf6 17.Nd5 Bxe6 18.Bh5+ Ng6 19.Qh6! Black may do best by returning the piece with 19…0-0-0 20.Bxg6 hxg6 21.Nxe7+. If Black returns the piece immediately with 15…0-0, then White retains a slight edge after 16.exd7 Bxd7 17.Bxf6 Bxf6 18.Nd5! b5 19.c4! with the initiative for White. Note that both 17.Rxb7 Ng4! and 18.Rxb7 Bc6 would give Black better chances for equality.

16.Bxf6 is the best attempt to obtain compensation for the piece. Note that 16.Be3 Nc4 gets White nowhere. Also 16.Rxf6 Bxf6! 17.Bh5+ Kd8 18.e7+ Kd7 is fine for Black.
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Again there are not many reasonable choices.

16…gxf6 is the better choice of recapture. In John Nunn’s book “Najdorf for the Tournament player”, he recommends 16…Bxf6 as the simplest line. There is no mention of 17.Rxb6! Qxb6 18.Nd5 with a very dangerous initiative for White. Black has three logical queen moves: a) 18…Qd8 19.Rxf6 wins; b) 18…Qc5 19.Rxf6! gxf6 20.Bh5+ Kd8 21.e7+ Kd7 22.Qh6! (threatening 23.e8=Q+ and 24.Qg7+). After e.g., 22…Qa5! 23.e8=Q+ Rxe8 24.Qg7+ Kc6 25.Bxe8+ Kc5 26.Qg3, White only has a small advantage; 
c) 18…Qd4 is best. White then has to avoid 19.Nxf6+? gxf6 20.Bh5+ Kd8 21.Qh6 Bxe6, when Black’s king would next go to the queenside and 22.Qg7 is met with the simple 22…Rg8. Better is 19.Bh5+ Kd8 20.Qa5+ b6 21.Nxb6, which appears to be winning outright for White. But after 21…Qc5!, White needs to trade queens and finds himself in an ending with only a small edge after 22.Qxc5 dxc5 23.Nxa8 Bxe6 24.Be2! The main idea of the last move is to play c4, Nb6 and Nd5, especially if Black’s bishop ever takes on a2.

17.Rxb6 sacrifices another exchange in order to gain access to the key d5-square.
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In the Sicilian Defense you will often have to defend with a calm heart.

17…Bxe6? tries to keep the d5-square covered. But the resulting position is not safe for your king after 18.Bh5+ and 19.Rxb7. If you need to defend a dangerous position, you might as well be up a whole rook and not just an exchange. Better try again.

17…Qxb6 is the only reasonable move.

18…Qd4 is a reasonable move, but probably not the best. White then has to play accurate to secure an edge with 19.Qh6!? Bxe6 20.Qg7 Bxd5 21.Qxh8 Bf8 22.Qxf6 (or 19.Bh5+ Kd8 20.Qa5+ b6 21.Nxb6 Qc5!, leading to queen trade and an unclear ending).

18…Qc5 gets the queen to the best square from which it eyes all the important dark squares. Note that 18…Qd8?? 19. Bh5+ Kf8 20.Qh6 leads to mate. Worth considering is 18…Qd4, when White has to play accurate to secure an edge with 19.Qh6!? Bxe6 20.Qg7 Bxd5 21.Qxh8 Bf8 22.Qxf6 (or 19.Bh5+ Kd8 20.Qa5+ b6 21.Nxb6 Qc5!, leading to queen trade and an unclear ending).

19.Bh5+ is White’s best try since 19.Qh6? Bxe6 is fine for Black.
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The tension of the position keeps increasing.

19…Kf8?? runs the wrong direction. White now mates your king with 20.Qh6+ Kg8 21.Bf7 and it’s over. Better try again.

19…Kd8 is the only try, since 19…Kf8?? leads to mate after 20.Qh6+.

20.Qh6 throws the queen into the attack and appears to be the only promising continuation. Clearly taking on f6 or e7 only helps Black, while 20.Bf7 h5! keeps White’s queen out of h6.
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A key moment of this line has arisen.

20…Bxe6?! is the obvious move one would look at first. Yet it is not the best. After 21.Qg7 Black faces a long defense ahead after e.g., 21…Re8 22.Bxe8 Bxd5 23.exd5 Kxe8 24.Qg8+. Try to get your queen to help out in the defense of your king with gain of time.

This queen move does not help you in the defense of your king. After 21.Qg7, White wins.

20…Qb5! activates the queen with gain of time. From b5, it now attacks the rook on f1, eyes the weak back rank via b1 and also gives Black the important option of moving the rook to e8 later and then recapturing on e8 with the queen. Note that White cannot play the desirable 21.Rxf6?? due to 21…Qb1+ with a bank rank mate. 
The obvious alternative 20…Bxe6?! still leaves Black with a long defense ahead after e.g., 21.Qg7 Re8 22.Bxe8 Bxd5 23.exd5 Kxe8 24.Qg8+. If 21.Kg1, then Black seems to have an advantage after 21… Bxe6 22.Qg7 Re8, e.g., 23.Nxe7 Qd7 24.Bxe8 Qxe7 25.Qxf6 Qxf6 26.Rxf6 Ke7. 
Clearly many of these lines are very tricky and there may well be improvements for either side on several occasions. Having played through one of the many tactical lines of the Poisoned Pawn Variations, you should now know whether you would feel comfortable defending such sharp positions. If you don’t want to face such wild positions, you could perhaps play the normal Bg5 Najdorf lines with 7…Be7 or explore the Polugaevsky Variation (7…b5 instead of 7…Qb6).