Pumped Up Kicks

Bruce Lee claimed not to be afraid of the man who had practiced 10,000 kicks once each, but the man who had practised one kick 10,000 times. This seems prima facie a case of fox versus hedgehog in martial arts, with the hedgehog being the one-trick pony and the fox being the one with a wide repertoire of moves. Without running simulations like the Discovery Channel did for tigers fighting lions and so on, let us try to derive a definitive result to this debate.

Strategically, it makes a big difference whether the opponent knows which single move the martial artist has practised to perfection. Even in wuxia novels, reputations about special moves were often commonplace, and we would expect total information openness in today’s world of internet and social media. If opponents know which move of yours is really deadly, they would be able to come up with countermeasures or simply avoid getting into positions where you could use that move, greatly reducing the effectiveness of your move, unless there is a certain inevitability to your move so they cannot avoid it. Of course, the enforced avoidance could lead them into other unfavourable positions, on which you can capitalise if you have other moves to make (in which case it would help if you had practised them too). Conversely, your reliance on that move might put you in similarly unfavourable positions.

You could always leave no survivors or witnesses, as some assassins have been known to do, which is quite a high moral cost to pay for your dependence on that move. Although if you didn’t do so, the deterrence provided might be valuable as well.

Other factors that affect our consideration include skill level of other moves, gains from practice, rate of deterioration, and effect relative to enemy defences. Diminishing returns from practice might mean that it is better to practise several moves and improve in each of them rather than hit a plateau on a single move. And if that move is already effective enough, such that practising it more doesn’t improve your ability to defeat opponents, then you should focus on something else. But if your skill in executing that move rapidly deteriorates in the absence of practice, then you might be forced to maintain your level by practising constantly.

There could be yet more benefits to practising other moves, such as helping you understand their limitations and seeing their place in the big picture, and also empathising with other practitioners of that move, who may be allies or opponents.

Thus far our discussion has been limited to one-on-one situations, which is an effect of the martial arts movie tendency to portray fights as either a one-on-one or serial one-on-ones. But depending on the capabilities of your allies, you might be better off specialising in a single move and filling a niche. And if you have to fight one-against-many, you might not be able to use your favoured move more than once.

It comes down to this. Real fights are messy and full of contingency and entropy and illegibility, unlike video games and movies which are by their nature understandable. Fighters are thus susceptible to Black Swans, and reliance on a single move is a recipe for Black Swans. Having practised more moves, you become robust rather than fragile. And that might be as much as one can wish for as a fighter.