BBC Micro versus PC at chess

If a BBC microcomputer met a Windows 10 PC for a game of chess, which machine would win?

Let's find out.

The contestants:

BBC microcomputer 32KB RAM, 2MHz 8 bit 6502 processor
Chess engine - Acornsoft Chess

Windows 10 PC 24GB RAM, 2.9GHz i7 64 bit Quad-core processor
Chess engine - Chess level 100

Chess Level 100 for Windows 10 (on the left playing black) V. Acornsoft Chess for the Beeb (on the right playing white)

I decided to start with both machines running on their lowest setting. Acornsoft Chess has ten levels of difficulty whereas Chess Level 100 has, erm... one hundred levels of play. The BBC machine was emulated using BeebEm on the Windows PC. I initially set the BBC difficulty to the highest possible, however, after waiting over ten minutes for it to make its opening move, I decided to drop the difficulty level for the sake of sanity. Both machines came to a gentleman's agreement that the Beeb would play white.

You can follow the game below, or download the PGN file to study on your own system or board.

1. Nf3 h6

Against United Nations security resolutions, the Beeb starts with the Zukertort Opening, keeping its options flexible. The PC responds with a dubious pawn defence. Maybe it doesn't know that there is a war on?

2. d3 d5
3. g3 Nc6
4. Nbd2 Bg4

Already the PC is on the offensive with bishop g4. The Beeb responds with an excellent defence from his own bishop.

5. Bg2 Qd6
6. O-O f5
7. Bh1 b5
8. Nh4 Nf6
9. Rb1 Qe6

PC has an active Queen and is attacking with its pawns. The Beeb is focussed on defence.

10. f3 b4

A superb attacking move from the Beeb threatens the black bishop, however, the PC makes the dubious pawn advance to b4. It was at this point that I realised that the PC was clearly outmatched by the Beeb. First blood went to the Beeb by capturing the neglected black bishop.

11. fxg4 Nxg4
12. Bf3 Nd4
13. Bxg4 Nxe2+

The PC ignores the bishop capture on g4 and sacrifices its knight for a pawn on e2.

14. Bxe2 Qe3+
15. Rf2 e5
16. Nxf5 Qc5
17. Bh5+ Kd8
18. Bf7 Qc6
19. h3 g5
20. b3 Rc8
21. Qf3 g4

The Beeb's white pieces are beginning to dominate the board as black makes another blunder with the g4 move.

22. hxg4 Be7
23. Qxd5+ Qxd5

The Beeb captures the pawn on d5 and forces a swap of queens. It is pretty much all over for the PC now but neither machines offered a ceasation to hostilities.

24. Bxd5 c5
25. Kf1 Rg8

A blunder from the PC puts the black rook in the firing line of the white bishop. Maybe fog of war or otherwise poor intel did not reveal the white bishop lying in wait like a sniper.

26. Bxg8 h5
27. gxh5 c4
28. dxc4 Kd7
29. Nh6 a5
30. Ke1 Rc5
31. Ke2 Rc8
32. Ke3 Bc5+
33. Ke4 Bxf2

The PC makes some good play and steals a rook at f2 with probably the only good move it made all game.

34. g4 Be1
35. Bd5 Rh8
36. Nf3 Rxh6

Another blunder from black coming up. The white knight on h6 is too much of a temptation and does not seem to realise it is covered by the white bishop on c1. The Beeb does not let it get away with this mistake.

37. Bxh6 Bf2
38. Kxe5 Kc7
39. Nd4 Bg3+
40. Ke6 Bf2
41. Bf4+ Kc8
42. Nf3 a4
43. bxa4 Bc5
44. Ng5 Bb6
45. Rxb4 Bc7

The breakthrough is complete. Black's king hides in his underground bunker and denies the reports of his generals that the enemy is massing at the gates.

46. Bb7+ Kd8
47. Nf7+ Ke8
48. Bxc7 Kf8
49. Bc6 Kg8
50. Bd5 Kf8
51. Nd6 Kg7
52. Ke5 Kh7
53. Nf5 Kh8

Moments before the end black's king has shuffled off into the corner to die.

54. Rb8+ Kh7
55. Rb5 Kh8
56. Rc5 Kh7
57. Ke4 Kh8
58. Rc6 Kh7
59. Rh6#
White wins.


So the winner of this battle was the BBC microcomputer running on the emulator. This did come as something of a surprise, but it teaches us very little. The Beeb played reasonable chess, it did not make any blunders and was both defensive and exploitative of black's errors. The PC running Chess Level 100, on the other hand, played very poor chess and was punished for it by the Beeb. It is important to note that both chess engines were playing at their very lowest settings. I am an average ability chess player and I can beat both of these programs with ease on their lowest settings. Clearly, the lowest level of Chess Level 100 is designed to be a pretty weak player.

If there is any interest in this post then I will maybe follow up with a game where both machines are playing at their very best. Important to note that the Beeb made all its moves in just over 5 minutes at this setting, yet it took over ten minutes to make a single move at the highest setting so it won't be a very quick game.

If you enjoyed watching this game, then you might want to let me know by writing something on the noticeboard or maybe you just want to read some more posts about chess


There is interest! Especially if you can get another win for the Beeb. It does seem difficult, if not notoriously difficult, to have a computer play weak chess without playing terrible chess.