The freeze-the-leg trick was specific to the mechanics of the war games. It followed from the following observations:

1. Different parts of the body could be hit independently without taking you out of the game entirely.
2. Getting hit in the legs more than once was no worse, tactically speaking, then getting it once.
3. Holding your legs in front of your chest could protect your more "vital" areas from being hit.
4. It's really tiring having to hold your own legs in the position required by Observation #3.

The idea of intentially shooting yourself in the leg the first three observations in to a tactic that negates Observation #4. It's the thought process that lead to the discovery of this particular tactic, rather than the tactic itself, that marks Ender as a strong candidate for leading the actual war.

The freeze-the-leg trick was specific to the mechanics of the war games. It followed from the following observations:

1. Different parts of the body could be hit independently without taking you out of the game entirely.
2. Getting hit in the legs more than once was no worse, tactically speaking, then getting it once.
3. Holding your legs in front of your chest could protect your more "vital" areas from being hit.
4. It's really tiring having to hold your own legs in the position required by Observation #3.

The idea of intentially shooting yourself in the leg follows from the first three observations to a tactic that negates Observation #4. It's the thought process that lead to the discovery of this particular tactic, rather than the tactic itself, that marks Ender as a strong candidate for leading the actual war.