Two fielders behind square is the rule that shapes every short-ball plan

The restriction almost nobody discusses on air is the one that decides whether a captain can bowl bouncers at all.

Everybody knows about the circle. Two out in the powerplay, then five allowed outside for the rest. Fine. The restriction that decides far more overs, and gets mentioned roughly never, is the limit of two fielders behind square on the leg side.

Think about what that means for a fast bowler with a short-ball plan. He wants to bang it in at the batter's ribs. The shots available are the pull, the hook, and the ramp. To protect the pull he needs deep square leg. To protect the hook he needs deep backward square or fine leg. That is already two, and both of them are behind square. So the moment he sets that field, he has used his entire allowance, which means the ramp over the keeper is completely unguarded and there is nobody at short fine leg either.

A batter who knows this, and they all know this, simply waits. He does not have to pull. He can walk across his stumps and help the ball over the keeper into an area where the rules have guaranteed there is nobody. That is not a low-percentage shot against a bowler who has committed to the short ball, because it does not require timing, only contact and direction.

The counter is to bowl the short ball wider, outside off, where the ramp is harder and the pull has to travel further. But wide and short is also a ball that can be cut, and now your off-side field is stretched too.

This is why you see so much back-of-a-length bowling into the body rather than genuine chest-high bouncers at the death. It is a compromise forced almost entirely by the leg-side rule rather than by anything about the pitch or the bowler.

And the extra bouncer per over that has been permitted in recent seasons has not changed this as much as people expected, precisely because the constraint was never how many short balls you were allowed. It was where you were allowed to put fielders when you bowled them. Give a captain a third man behind square on the leg side and the short-ball plan becomes genuinely threatening overnight.

Whether that would be good for the game is a separate argument, and I suspect the administrators would rather not find out. But if you want to understand why a bouncer barrage that looks unplayable in a Test match looks toothless in a T20, that is your answer, and it has nothing to do with courage.