Umesh P. Narendran

Impossible moves

Sometimes, we encounter some very unexpected moves in chess games, which are not only not obvious, but are deceivingly improbable-looking. This is very common in composed problems and endgame studies, because it is considered to be a plus for the quality of the composition. It sometimes happen in actual games as well.

This article deals with a few of them.

1 Problems

While evaluating chess problems for tourneys, one of the criteria is the unexpectedness of the key move. A key that looks extremely bad turns out to be the only move to win in the stipulated number of moves. As a result, we can see hundreds of chess problems with “good key” or “unpredictable key”.

Here, a few two-movers are dealt with. In two-movers, giving a key that gives Black too many choices is hard: White has only one move to checkmate, and will need to find a mate for every Black defence.

Position 1

Position 1 is an example. White to move. Mate in two.
McDowell, Michael (Problem)
The Problemist, 1986

Position 2

This position shows another such key move, that leaves several pieces en prise, and giving the Black King flight squares.

White to move. Mate in two.
Shinkman, William A. (Problem)
Dubuque Chess Journal, 1873

Position 3

Position 3 allows Black to check the White King multiple ways.

White to move. Mate in two.
Guidelli, Giorgio. (Problem)
2nd pr, Eco degli Scacchi, 1917

Position 4

Some two-movers have a sacrificial key where the piece giving the key move can be captured in multiple ways. Position 4 is an example.

White to move. Mate in two.
van Dijk, NGG (Problem)
8th Hon. mention, 3rd FIDE tourney, 1961

Position 5

There are some peculiar stories about some chess problems. It cannot be taken at face value, but the following is amusing.

Position 5 is a problem composed by the famous Problemist and puzzle maker Sam Loyd.

The story goes like this: Sam Loyd asked a friend: "This is a mate in 5 problem. What is the white unit that is the least likely to deliver mate on the fifth move in the main line?" The friend looked at the position and said, "The pawn on b2."; It is not clear how that pawn can give a check on the fifth move, forget the checkmate! But it turns out that it delivers the checkmate in the main line!

White to move. Mate in five.
Loyd, S. (Problem)
1858

2 Endgame studies

Endgame studies are also composed problems, but they are closer to actual games. Also, by design, all White moves, not only the first key move, should be the only way to win (or draw) in that position. Having unexpected moves as key is a delight in such problems.

Position 6

Position 6 has a beautiful study with just six units.

White to play and win Blundell, David (Problem) 1^st prize, diagrammes, 1995

In this minimal setting, there are a number of zugzwangs and only moves. The ending is very instructive.

Here are some points to consider:

1. White cannot afford to lose the pawn on e4.
2. White can lose his Knight, if he captures both Black pawns, preserve his pawn, and the WK can forward enough to support the pawn for queening.
3. White should not allow the BP to queen without getting captured immediately.

Before getting into the solution, let us examine some interesting positions: In Position 7, with move, White wins with 1.Kxf2, but with Black to move, Black draws by
1...f1Q+! 2.Kxf1 Ke3! 3.Ke1 Kd3! 4.Kd1 Ke3! 5.Kc2 Kd4!
And White cannot get to the Black pawn. In Position 8, with White to move, it is a draw: 1.Ke2 reaches Position 7 with Black to move. But with Black to move, it is a zugzwang.

1...Kg3
1...Kg4 2.Ke2 Kg3 3.Kf1 +- 2.Ke2 Kg2 3.Nf1 +-

In Position 9 above, White to play can only draw: 1.Nd2+ Kf4 reaches Position 8.

With Black to move, all moves lose.

1. 1...Kg2 2.Ke2 Kh1 (2...Kg1 3.Ne3 +-) 3.Kf3 (3.Kxf2? stalemate) 3...Kg1 4.Nd2 +-
2. 1...Kf4 2.Nd2 +-, as Position 8 is reached with Black to move
3. 1...Kg4 2.Ke3 (2.Kc4 also wins.) wins the pawn and the game

But Position 10 below is a draw, irrespective of whose move it is. Position 10 is a draw, irrespective of whose move it is. With White to move, 1.Ke2 f1Q 2.Nxf1 Kxe4 draws.
1.Nf1 Kf3 Zugzwang reaches Position 9 and draws.

With move, Black draws by
1...Kg3! 2.Nf1+ Kf3 Zugzwang 3.Nd2+ Kf4 Zugzwang reaching Position 8 with White to play, drawing.

With the Knight on d2, the situation is a little different. See Position 8.

Now let us come back to the problem.

Trial 1

1.Kc1? f3 2.Kd2 f2 3.Ke2 Kg4 4.Ne3+
4.Kxf2 Kf4 wins the pawn and draws.
4...Kf4
4...Kg3 also draws.
5.Kd3
Reaches Position 10. It is a draw.

Trial 2

An interesting idea to win is to get the Knight to d2, from where it supports e4 and controls f1, so that the King can go up or to the right to win one of the Black pawns. One way is Nc2-a3-c4-d2.

1.Na3? f3 2.Nc4 Kg5
2...Kh4 also draws, but 2...Kg4? 3.Kc2 Zugzwang Kg3 4.Kc3 Zugzwang Kg4 (4...Kf4 5.Kd3 +-) 5.Nxe5+ Kf4 6.Kd4 f2 7.Nd3+ +-
2...f2? also loses to 3.Nd2 Kg4 4.Kc2! Kg3 5.Kc3 Kg2 6.Kc4 +-
3.Kc2
3.Nd2? Kf4 4.Kc2 Ke3 =
3...Kg4 Zugzwang 4.Kc3
4.Nd2 Kf4! 5.Kd3 f2 Zugzwang, draws by reaching Position 8 with White move.
4...Kg3
4...Kg5 also draws.
Compare this position with the solution, where the White Knight is on b3 and White can play 5 Kc4.

5.Kd3
5.Nxe5?? f2 -+
5...Kf4
5...f2 6.Ke2 Kf4 7.Nd2 also is a draw, by reaching the Position 7 with Black to move.

Black draws. 6.Nd2 f2 is Position 8, while 6.Ne3 f2 is Position 10, both with White to move. Both are draws.

The Solution

Position 11

Position 11 offeres a hard study to solve, where each White move is the unique way to win, and most of these moves are very unexpected.

Evreinov, Viktor (Problem)
1959 An unbelievable key, and an incredible continuation, where there is only a single series of moves that wins!

Position 12

Position 12 shows a very surprising key in a simple setup.

Sarychev, A.K. (Problem)
1922 White to play and draw.

3 Real Games

Unbelievable moves happen in real games as well. Here are some examples.

Position 13

Topalov, V. – Shirov, A.
Linares: 1998
Position 13: Black to play and win.

Black has two extra pawns, but this is an opposite-color Bishop ending, and every chess player knows how difficult to win this ending. For example, 1...Bg4 2.Kf2 Kf5 3.Ke3, it is not possible for Black to make any progress. Or, 1...Bb1 2.Kf2 f5 3.Ke3 Kd6 4.Kd4 and White controls the center so well that Black cannot take advantage of his material advantage.

What is the correct strategy to win?

It turns out that there is only one move to win, and Shirov found it on the board!

47...Bh3!!

Black vacates the f5-square for the King, without giving White the time to play 48.Kf2 For example, 48.Kf2 Kf5 49.Kf3 (49.Ke3 Bxg2 gains one more pawn, and the f-pawn will be a third passed pawn.) 49...Bxg2+ 50.Kxg2 Ke4 and wins as in the game.

48.gxh3 Kf5! 49.Kf2 Ke4! 50.Bxf6 d4! 51.Be7

51...Kd3!

Threatening 52...Kc2 followed by marching the d-pawn down. The Bishop cannot prevent both the pawns.

52.Bc5 Kc4 53.Be7

So that 53...d3? can be met with 54.Ke1 Kc3 55.Kd1, drawing.

53...Kb3!

White resigns. Black threatens 54...Kc2, and 55.Bc5 is met with 55...d3 56.Ke1 (56.Ke3 Kc2 57.Bb4 a3 58.Bxa3 d2 -+) 56...Kc2 57 Bb4 a3 58 Bxa3 d2+ -+.

Position 14

Position 14 shows a very bizarre first move.

Khismatullin, D. – Eljanov, P.
Jerusalem: 2015
Position 14: White to play and win.

With ...Qxd1# threatened and the presence of a menancing d-pawn makes White’s position appear too hopeless. How can White win from this position?

44.Kg1!!

An unexpected move, saving the King by giving up a whole Rook!

44...Qxd1+ 45.Kh2

Unbelievable! Black is lost here. Since both Qxd6 and c7 are threatened, Black’s reply is forced.

45...Rxc6 46.Qe7+

In the actual game, White was gaining time. 46.Qxf7 wins, as happened in move 48.

46...Kh6 47.Qf8+ Kg5 48.Qxf7

White is threatening both 49.Qf4# as well as 49.f4+ Kh6 50.Qf8+. Black gives up the Rook to avoid checkmate.

48...Rf6 49.f4+ Kh6 50.Qxf6

Now Black is lost. 50...Qe2 51.Qf8+ Kh5 52.Qg7 h6 53.Qe5+ Kh4 54.Qf6+ Kh5 55.f5 gxf5 56.Qxf5+ Kh4 57.Qg6

Black resigns.

Position 15

Position 15 is from a very famous game, where, in a middle game with so many pieces, the White King enters the battle which is quite unexpected.

Short, N. – Timman, J.
Tilburg: 1991
Position 15: White to play and win

Black has a cramped position, and definitely White has an advantage. He needs one more piece to help the Queen to deliver a mating attack. But which piece? 1.Ng5?? is not possible due to the mate on g2. Then which piece?

32.Kg3!!

The idea is to march the King through g3-f4-g5-h6 and checkmate with Qg7. Surprisingly, Black doesn’t have a defense. The Rook on f8 cannot move due to Qxf7+, while moving the Queen to c1 via c5 and a3 can be met be placing the Knight on d2.

The game continued

32...Rce8 33.Kf4 Bc8 34.Kg5

And Black resigned.

Position 16

Position 16 is a famous position, often quoted to show the power of a pin.

Schatz – Giegold
Hof: 1928
Position 16: Black to play and win.

As the Black player, every chess player would consider 1...Qh7+ but would immediately reject it due to 2.Rh3, pinning the Queen. But it turns out it has more venom that it seems first.

1...Qh7+! 2.Rh3

2.Kg1 Rxd3 wins a piece.

The Queen is pinned, but she is not immobile. She can move, capture, check and checkmate. This game shows all of that.

2...Rd1+

Reversing the moves won’t work: 2...Qxh3+? 3.gxh3 Rd1+ 4.Kh2 Rh1+ 5.Kg3 +-

3.Kh2

3...Rh1+! 4.Kg3

After 4.Kxh1, 4...Qxh3+ 5 Kg1 Qxg2#

The Black Queen is pinned, but not immobile!

4...Qh4+

4...Rxh3+ 5.gxh3 Qh4# also will work.

5.Rxh4 gxh4#

Position 17

Sometimes, computer analysis reveals such incredible moves, which are not spotted in the game. Position 17 an example from one of my games from a blitz championship.

Umesh – Derek
Pleasanton, USA: 2020
Position 17: White to play.

Black has just captured a White pawn on f6 by the Knight, and the game continued 19.gxf6 Bxf6 and the game lasted another thirty moves till I won with less than 2 seconds on my clock.

It looks like there are no alternatives other than 19.gxf6 in this position, but computer analysis shows that

19.Rdf1! wins immediately, with the following continuations:

A) 19...Ng4 20.Qxf8+!! Kxf8 21.Nxe6+ +-
B) 19...Nd7 20.h5 Nc5 21 Rf6! +-
C) 19...Ne8 20.Nxe6 +-

Position 18

No article discussing impossible moves will be completely without the famous Levitsky - Marshall game

Levitsky – Marshall
Breslau, GER: 1912
Position 18: Black to play

Black, who has just captured a Bishop on h3, is a piece up (Capturing the rook will lose the Queen by ...Nf3+), and has many ways (for example, 23...Qb2, and win with the extra piece, so it doesn’t fall into the theme of this article. However, the move played by Marshall does deserve the title of an impossible move!

23...Qg3!! White resigns.Black is threatening checkmate by 24...Qxh2+. The Queen can be taken in three ways, each leading to White’s defeat.

A) 24.hxg3 Ne2#
B) 24.fxg3 Ne2+ 25.Kh1 Rxf1#
C) 24.Qxg3 Nxe2+ 25.Kh1 Nxg3+ 26.Kg1 (26.fxg3 Rxf1#) 26...Ne2+ 27 Kh1 Rc3 wins. Here, Black wins by the piece he already won, and not with the combination.