Alan Turing was not only a brilliant mathematician and computer science pioneer, but also a gifted runner (with a marathon time of 2:46). It is no wonder, then, that he invented a game that combines rigorous thinking and running: Round-the-house chess.

The rules are as follows: It looks almost like a normal game of chess, except instead of opponents taking turns in playing, each player has to run around the house once before being allowed the next move. If you overtake your opponent, you get two moves in a row.

For those living in or near Cambridge (UK), my former colleague Daniel Murrell is organising a Turing chess tournament this coming weekend (Sunday, 23 June) to honour Turing’s 101st birthday.

Now, I am not a good chess player and not a fast runner, but I think the idea of the game is intriguing. Though it is not entirely clear how the game was intended to be played, and there is some discussion about the rules, it looks like the version played on Sunday makes two moves in a row possible if you manage to outrun your opponent.

This raises some interesting tactical issues, at least it did when I discussed it with my boyfriend (both a good chess player and a fast runner) over a few glasses of red wine. Here are a few thoughts we came up with:

• Overtaking once: If you manage to overtake your opponent, you get to move twice in a row, and your opponent basically loses a move. A better chess player will be able to cope with losing the occasional turn if that does not happen too often. A better runner, if he or she gets a high enough number of double-turns, will gain a large cumulative advantage. A sufficient number of “double-turns” would very probably turn any game around, although we are not sure about what that number would need to be. Note also that if you check a king and then outrun your opponent, you can win the game immediately.
• Overtaking twice: We predict that a “triple-turn” would definitely turn the game around. This is quite unlikely though, because it would mean overtaking your opponent twice on a lap around the house. Depending on the relative running speeds of the two opponents and the length of the distance “around the house”, this is possible (especially accounting for the fact that less experienced runners might tire out towards the end of the competition and may have to walk their laps instead of running them.) You would have to move while your opponent is just starting their lap, overtake them towards the beginning of their lap, move again, overtake them towards the end of their lap and move again. Those two laps are probably the fastest you’ll run in the whole game, but totally worth it. (This also means that it might be advisable to slow down earlier in the game in order to allow this situation to come about).
• Playing quickly: The time you take between two moves is determined not only by how fast you can run around the house, but also on how much time it takes you to think about your next move. Depending on which is faster, your fitness or your ability to play Blitz chess becomes the limiting factor. In any case, it pays off to have openings memorised so you don’t waste time thinking towards the beginning of the game.
• When to do your thinking: If your opponent is not a fast runner, you can afford to run slowly yourself (as long as you are about as fast as them, you just take turns. If you are a bit faster, you’ll get the occasional double move). Running slowly gives you time to think while you run. Running faster gives you more time to think while in front of the board, but makes it much harder to think while you’re running. (If I understand correctly, combining thinking with physical exertion is one of the challenges of Chess Boxing). In any case, being good at remembering the state of the chess board when last you saw it will give you an advantage.
• Length of the lap: This comes down to the question: How big is the house you run around? I wouldn’t suggest playing the game in the Winter Palace or anything, but even with normal-sized houses there is quite some variability. (Also, if the game is played in a park rather than an actual house, organisers are basically free to choose the length of the lap). Smaller laps make differences in running speed less obvious, and will mean time spent thinking (i.e. proficiency at chess) is probably the limiting factor. Larger laps mean running skill becomes more important. Even if the house is small, distances will add up, though. Take a 50m lap, and a chess game that takes 40 moves, then that’s 2k run for each game. Depending on the mode of the tournament (the one on Sunday is a double-knockout), and on how far you make it in the competition, you could easily run 10k or more. Most of the laps will probably be run at full speed, and stops in between (especially at the beginning) will be quite short, so it’s like doing 10k’s worth of intervals with minimal recovery in between. Quite a workout! A longer lap (and more games in the tournament) means that at some point, this becomes a running endurance event, as well as a running speed (and chess) event. Slower runners with more endurance might have their revenge towards the later stages (if they make it that far).

That’s our theory. It would be interesting to see how a tournament like that unfolds and what other moves and issues come to light when more of these games are played. Unfortunately, I can’t drop by the game on Sunday (what with living on another continent and all that), but if you do, I’d love to hear a post-game report!

Good luck to all runners, chess-players, and hybrids thereof!