Missed tactics, part 4

It's that time of year again when my skin gets darker and my hair gets whiter -- the former on account of longer and sunnier days, the latter on account of mounting pressure at work. It's also a time of year when I don't get nearly enough sleep, and that is a recipe for poor chess performance.

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1. 2024-05-04

Black to move
(1.d4 Nf6 2.c4 e6 3.f3)

In this position, from an anonymous Lichess Rapid game, White just played 11.a4. How should I have replied?

Explanation: White has two pieces targeting Black's bish on e7, and it looks like Black's f6-knight is pinned. Black, however, has the opportunity to win a pawn. How so? Black has a move that captures a pawn, discovered-attacks White's undefended g5-bish and double-defends the bish on e7. After 11...Nxd5, whichever way White captures back, Black emerges a pawn up: 12.Bxe7 Nxe7 / 12.Nxd5 Bxg5+ / 12.Rxd5 Bxg5+ / 12.cxd5 Bxg5+.

Solution: 11...Nxd5

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2. 2024-05-06

Black to move

In this position, from an anonymous Lichess Rapid game, White just played 33.cxb4. How should I have replied?

Explanation: Black has a passed pawn on c4, but White can create his own passed pawn after pushing 34.a4. If Black retreats with 33...Kc5 and White continues 34.Kd4, then correct play on both sides leads to a draw. What Black needs to do is force White's king away from the all-important c4-pawn. Only one move does this: moving the king to e5. How so? Through the concept of shouldering. If White retreats with 34.Kd2, Black's king advances with 34...Kd4 and shoulders the c-pawn to promotion. If instead White tries to buy time with 34.h3, Black's king returns to d5 and now White's king is effectively forced to retreat to the second rank; and after the Black king advances to d4, the king again shoulders the c-pawn to promotion.

Solution: 33...Ke5

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3. 2024-05-13

Black to move
French Defense: Advance Varation

In this position, from an anonymous Lichess Rapid game, White just played 18.Bf2. How should I have replied?

Explanation: The difficulty in this tactic is seeing three moves ahead when the first move isn't a check, a capture or a threat to win a piece. If this were a puzzle themed "Mate in three," the approach would different. How so? The key to seeing the tactic is integrating two realities: the pin on White's f3-bish and the vulnerability of White's pawn on g2. Since the f3-bish is pinned, White isn't defending the h4-square; and since Black can use the h4-square to double-attack White's g2-pawn, moving the knight to h4 threatens allows the queen to capture on g2 with mate.

Solution: 18...Nh4

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4. 2024-05-14

White to move
(Dutch Defense)

In this position, from an anonymous Lichess Rapid game, Black just played 24...Kg8. How should I have continued?

Explanation: Black is threatening to capture White's rook with 25...Nxc2 or a discovered attack on White's queen with 25...Bb3. Black is also triple-defending the c8-square, which is where White would like to land his c2-rook. As it turns out, the configuration of Black's pieces vis-a-vis c8 and the unavailability of g8 for Black's queen are what give White a tactical opportunity. How so? After an exchange of rooks on c8 with 25.Rc8 Raxc8 and 26.Rxc8, Black cannot reply 26...Rxc8 due to the fork with 27.Qxe6+; nor can Black reply 26...Bxc8 due to the fork with 27.Qxe8+. Black's best reply after 25.Rc8 is 25...Qg6, defending the e6-bish -- but after 26.Rxa8 and 26...Rxa8, What attacks Black's rook with 27.Bxb7 and then wins the knight on e3 with 28.fxe3.

Solution: 25.Rc8

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5. 2024-05-28

White to move
(Queen's Gambit)

In this position, from an anonymous Lichess Rapid game, Black just played 30...exd5. How should I have continued?

Explanation: Black is threatening two dangerous checks, namely 31...Qb6+ and 31...Re1+. Neither check leads to an immediate mate, but White has only one move that avoids a losing position.

Solution: 31.Qxh6

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6.