Poole versus HAL 9000

In the movie 2001: A Space Odyssey, the astronaut Frank Poole is seen playing chess with the HAL 9000 supercomputer. As HAL is supposed to be infallible, no one is surprised when HAL soundly defeats Poole (though the novel does mention that HAL is programmed only to win 50% of the time in order for there to be some point in the astronauts ever playing). The director Stanley Kubrick was a passionate chess player, so unlike many chess scenes shown in other films, the position and analysis actually makes sense. The actual game seems to come from Roesch - Schlage, Hamburg 1910, a tournament game between two lesser-known masters.

Game score

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

Position before 14. Qa8xa6, where the movie picks up the game.

Opening: Ruy Lopez, Worrall Attack

1.e2-e4 e7-e5 2.Ng1-f3 Nb8-c6 3.Bf1-b5 a7-a6 4.Bb5-a4 Ng8-f6 5.Qd1-e2 b7-b5 6.Ba4-b3 Bf8-e7 7.c2-c3 O-O 8.O-O d7-d5

This move is a pawn sacrifice. After White accepts it, Black's pieces can occupy active positions.

9.e4xd5 Nf6xd5 10.Nf3xe5 Nd5-f4 11.Qe2-e4 Nc6xe5 12.Qe4xa8?

This move deflects the queen, allowing Black to mount a kingside attack. White is also worse if the queen takes one of the knights, which could be answered by N-d3 or Be7-d6. The correct move is 12.d2-d4, to which Black should reply with 12... Bc8-b7.

12... Qd8-d3

Threatening 13... Nf4-e2+ 14. Kg1-h1 Ne2-g3+ with mate to follow.

13.Bb3-d1 Bc8-h3!

Black also has 13... Bc8-g4, winning a piece after 14. Qa8-b7 Bg4xd1 15. Rf1xd1 Nf4-e2+ 16. Kg1-h1 Ne5-g4 17. Qb7-f3 Qd3xf3 18. g2xf3 Ng4xf2+, or 13... Nf4-h3+ winning the queen after 14. g2xh3 Bc8xh3 with the dual threat of mate & Rf8xQa8. The movie picks up the game here — see the diagram.

14.Qa8xa6?

White abandons the long diagonal and moves into a forced mate. Even after 14.Qa8-b7 c7-c6 15.Qb7xe7 Bh3xg2 16.Rf1-e1 Ne5-f3+ 17.Bd1xf3 Qd3xf3, mate is not far off.

14... Bh3xg2 15.Rf1-e1 Qd3-f3

Here HAL, using the descriptive chess notation, says: "I'm sorry Frank, I think you missed it. Queen to bishop three, bishop takes queen, knight takes bishop, mate.", which is inaccurate in two ways. In the first place, the move Qd3-f3 isn't "queen to bishop three" but "queen to bishop six". Secondly, HAL's variation 15.Qd3-f3 16.Bd1xf3 Ne5xf3# does not mention that White could prolong the resistance for a few moves, for example by playing 16.Qa6-h6. Some conjecture that these two inaccuracies are a very subtle foreshadowing of either HAL's breakdown or of his deception of the crew.

Poole resigns without questioning HAL's analysis.

See also

• Computer chess

External links

• Murray S. Campbell: "An Enjoyable Game:" How HAL Plays Chess in: e-book HAL's Legacy (1996)
• Tim Krabbé: Willi Schlage The only unknown to become immortal twice. (1999)