The Poisoned Pawn Variation is any of several chess opening variations where a pawn

Pawn (chess)

The pawn is the most numerous and weakest piece in the game of chess, historically representing infantry, or more particularly armed peasants or pikemen. Each player begins the game with eight pawns, one on each square of the rank immediately in front of the other pieces...

 is said to be "poisoned" because its capture can result in positional problems or material loss for the captor. The best known of these, called the Poisoned Pawn Variation, is a line of the Sicilian Defense, Najdorf Variation that begins with the moves:

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. Bg5 e6 7. f4 Qb6 after which 8. Qd2 Qxb2 usually follows, accepting the "poisoned" . White can also play 8. Nb3, protecting the pawn.

History

One of the pioneers of this line was David Bronstein

David Bronstein

David Ionovich Bronstein was a Soviet chess grandmaster, who narrowly missed becoming World Chess Champion in 1951. Bronstein was described by his peers as a creative genius and master of tactics...

, who tied the 1951 World Championship

World Chess Championship

The World Chess Championship is played to determine the World Champion in the board game chess. Men and women of any age are eligible to contest this title....

 match against Mikhail Botvinnik

Mikhail Botvinnik

Mikhail Moiseyevich Botvinnik, Ph.D. was a Soviet and Russian International Grandmaster and three-time World Chess Champion. Working as an electrical engineer and computer scientist at the same time, he was one of the very few famous chess players who achieved distinction in another career while...

 12–12. Bobby Fischer

Bobby Fischer

Robert James "Bobby" Fischer was an American chess Grandmaster and the 11th World Chess Champion. He is widely considered one of the greatest chess players of all time. Fischer was also a best-selling chess author...

 later became an exponent, playing it with great success.

The line was most famously played in game 7 and game 11 of the 1972 World Chess Championship Match between Fischer and Spassky

Boris Spassky

Boris Vasilievich Spassky is a Soviet-French chess grandmaster. He was the tenth World Chess Champion, holding the title from late 1969 to 1972...

. In both games Fischer played Black and grabbed the pawn. In the first, he reached a secure position with a comfortable material advantage but only secured a draw

Draw (chess)

In chess, a draw is when a game ends in a tie. It is one of the possible outcomes of a game, along with a win for White and a win for Black . Usually, in tournaments a draw is worth a half point to each player, while a win is worth one point to the victor and none to the loser.For the most part,...

. In the second, Spassky surprised Fischer with a theoretical novelty and won the game after Fischer defended poorly, allowing Spassky to trap Fischer's queen, handing Fischer his only loss with the Poisoned Pawn.

The line was later taken up successfully by other leading players, including World Champions Garry Kasparov

Garry Kasparov

Garry Kimovich Kasparov is a Russian chess grandmaster, a former World Chess Champion, writer, political activist, and one of the greatest chess players of all time....

, Viswanathan Anand

Viswanathan Anand

V. Anand or Anand Viswanathan, usually referred as Viswanathan Anand, is an Indian chess Grandmaster, the current World Chess Champion, and currently second highest rated player in the world....

, and even Anatoly Karpov

Anatoly Karpov

Anatoly Yevgenyevich Karpov is a Russian chess grandmaster and former World Champion. He was the official world champion from 1975 to 1985 when he was defeated by Garry Kasparov. He played three matches against Kasparov for the title from 1986 to 1990, before becoming FIDE World Champion once...

. It remains one of the most theoretically important

Chess theory

The game of chess is commonly divided into three phases: the opening, middlegame, and endgame. As to each of these phases, especially the opening and endgame, there is a large body of theory as how the game should be played...

 variations of the Sicilian Defense. In recent times, the line has become a popular battleground in computer chess

Computer chess

Computer chess is computer architecture encompassing hardware and software capable of playing chess autonomously without human guidance. Computer chess acts as solo entertainment , as aids to chess analysis, for computer chess competitions, and as research to provide insights into human...

, with operators trying to "out-book" each other by going progressively deeper into the different Poisoned Pawn lines. As a result, the line is extremely well researched, and seems to be a draw given perfect play from both sides.

Other lines

A Poisoned Pawn variation also exists in the French Defence Winawer: 1. e4 e6 2. d4 d5 3. Nc3 Bb4 4. e5 c5 5. a3 Bxc3+ 6. bxc3 Ne7 7. Qg4 Qc7 8. Qxg7 Rg8 9. Qxh7 cxd4 10. Ne2 Nbc6 (or 10. Kd1 Nd7). Like the Poisoned Pawn variation in the Sicilian Najdorf, this line gives significant weaknesses for both sides and can lead to highly complex lines. White can attack on the kingside and try to exploit the passed h-pawn, while Black destroys the centre.

There is also a Poisoned Pawn variation in the Latvian Gambit

Latvian Gambit

The Latvian Gambit is an aggressive but dubious chess opening, which often leads to wild and tricky positions. This opening is uncommon at the top level of over-the-board play, but some correspondence chess players are devoted to it...

: 1. e4 e5 2. Nf3 f5 3. Bc4 fxe4 4. Nxe5 Qg5?! This variation leads to extremely sharp play, is considered rather dubious, and is thus rarely seen today. However, Graham Burgess

Graham Burgess

Graham K. Burgess is an English FIDE Master of chess and a noted writer and trainer. He became a FIDE Master at the age of twenty. He attended Birkdale High School in Southport, Merseyside. In 1989 he graduated from the University of Cambridge with a degree in mathematics...

states that it "is not utterly, clearly bad."