When 2001 was filmed, descriptive notation of chess moves was still quite common; nowadays algebraic notation is the standard worldwide. In algebraic notation every square on the chessboard has a unique name, as shown in figure 5.8. Moves are written with the letter for the piece first, followed by the destination square for the piece. For pawn moves there is no piece symbol. As in descriptive notation, kingside castling is denoted 0-0.

Kubrick and Clarke used the game Roesch-Schlage, Hamburg, 1913 as the source of the chess position and moves played between Frank and HAL. Here is the record of the full game.

White, played by Frank, moves first; HAL is Black.

1. e4 e5 2. Nf3 Nc6 3. Bb5

These moves signal the Ruy Lopez, one of the most popular openings in grandmaster play.

3... a6 4. Ba4 Nf6 5. Qe2

Frank chose the Worall variation. This move is much less common than the standard 5. 0-0.

5... b5 6. Bb3 Be7 7. c3 0-0 8. 0-0 d5 9. exd5?!

The notation ?! means "a dubious move." 9. exd5 is quite risky, and the move 9. d3 is the almost universal choice among top players.

9.... Nxd5!?

The !? notation means "an interesting move." HAL plays an extremely aggressive and trappy move, perhaps having learned after many games with Frank that such aggression usually pays off. Opening books recommend the move 9. ... Bg4 in this position.

10. Nxe5 Nf4 11. Qe4 Nxe5 12. Qxa8??

This is the losing move. If Frank had played 12. d4 he would have had a small advantage, which is why 9. .. Bg4 is generally considered to be the best move. Here is one clue to HAL's method of playing chess: he chooses a nonoptimal move at move 9, which creates a difficult situation for Frank, one in which it is easy to make a mistake. Current computer chess programs are just beginning to take such considerations into account.

12.... Qd3!

Deep Blue would see this strong move in about one second. Frank no longer has any real defense.

13. Bd1 Bh3

According to Deep Blue, 13. ... Nh3 would have forced a checkmate one move sooner. The position after 13. ... Bh3is where the movie picks up the game (see figure 5.9).

14. Qxa6

This allows a checkmate in five moves. All the moves HAL plays in the movie would be found in a fraction of a second by Deep Blue.

14. .. Bxg2 15. Re1 Qf3!, and White resigns (see figure 5.10).

A pretty queen sacrifice to finish the game. HAL gives the continuation16. Bxf3 Nxf3 mate.There were various ways to postpone the checkmate a couple of moves (e.g., 16. Qc8 Rfc8 17. h4 Nh3 18. Kh2 Ng4 mate).