A trap in the Classical Sicilian

In the Classical Sicilian (1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 d6), 6.f4 is a fairly rare choice by White. Mega Database 2013 shows it as being only White's seventh most popular move, after 6.Bg5, 6.Bc4, 6.Be2, 6.Be3, 6.f3, and 6.g3. Black can respond with 6...g6, transposing to the Levenfish Variation of the Sicilian Dragon; 6...e5, intending to reach a Boleslavsky Sicilian-type position; and 6...e6, among others. According to Mega Database 2013, 6...e5 is the best-scoring of Black's major moves, with White scoring only 47.2% in 287 games. (White scores 51.1% in 321 games against 6...g6, and 55.5% in 267 games against 6...e6.)

White's best response to 6...e5 is 7.Nf3. My opponent played instead 7.Nxc6 bxc6 8.fxe5, presumably intending to respond to 8...dxe5 with 9.Qxd8+ with a favorable endgame for White (58.3% in 12 games, according to Mega). I instead responded with the much stronger 8...Ng4! (White scores only 33.3% in 18 games), offering a gambit that White should decline (as almost everyone does) with 9.Be2!, when Black has a very pleasant position after 9...Nxe5. Instead, White greedily took the pawn with 9.exd6? After 9...Bxd6, White's position was very unpleasant, with Black's bishop and knight trained on White's kingside and Black threatening to introduce the queen into the attack with 10...Qh4+ or 10...Qc7. White should try 10.Bg5! f6 (10...Qxg5 12.Qxd6) 11.Bh4 0-0 12.Bc4+, when he stands much worse but could play on. Instead he found 10.h3?? and then resigned, evidently having realized that 10...Qh4+ is crushing (10...Bg3+ also wins), e.g. 11.Kd2 Bf4+ 12.Kd3 (12.Ke2 Qf2+ 13.Kd3 Ne5#) Ba6+ 13.Nb5 0-0-0+, winning boatloads of material.

One should never play a blunder like 10.h3??, especially in a correspondence game. Alexander Kotov in his famous book Think Like a Grandmaster explained that once having decided on one's move, one should look at the position "through the eyes of a patzer" and ask questions like, "Does he threaten mate? Do I have a piece hanging? Am I overlooking a check he can play?" and so forth. This is not always possible in over-the-board games with fast time controls, but one should always do this in correspondence games.

I'm now 69-0 on GameKnot, but will have to give up a draw soon.

A trap in the QGD Exchange Variation

In the first round of the 1949 Soviet Championship, the young Tigran Petrosian fell into an elementary trap against Alexander Kotov. Kotov's 7.Qc2! is an important finesse, since the natural 7.Bd3 allows Black to exchange pieces with 7...Ne4!, when White has little or no advantage. Petrosian, likely suffering from first-round jitters, played 7...Ne4?? anyway, but after 8.Bxe7 Qxe7 (the abject 8...Kxe7, immediately surrendering a pawn to 9.Nxe4 dxe4 10.Qxe4+, looks like a slight improvement) 9.Nxd5!, Black was losing at least two pawns, and could have resigned already. He did so on move 13, the shortest loss in the career of "Iron Tigran."

Petrosian later became known as one of the world's hardest players to beat. Of over 100 games in Chess Olympiads, he lost only one. He reigned as World Champion from 1963 to 1969. When he beat Spassky in 1966 to retain his title, he became the first sitting World Champion since Alekhine's victories over Bogolyubov in 1929 and 1934 to actually win a World Championship match.