I think the OP was slightly unclear in his post, but there are definitely different types of smashes.
1. Jumping and actively looking to hit the shuttle as high as possible - this leads to the steepest smash, which can be doubly deadly when combined with an accurate angle (attacking the sides). I believe this is the standard in singles, where angles are more important than raw speed.
2. Jumping, "waiting", then hitting the smash lower with the added gravity / body-weight power. This leads to a flatter, faster smash (huge sound). This is effective when mixing up attack, aiming for the center of the court or their body. This variation is popular in doubles, and I've seen many tall players rip through the shuttle using this method.
^^ In that case, best still to take it early if you can, for several reasons:
1. Speed. If doubles, speed is paramount as others have already pointed out. The speed of your shot from the front is much faster than from the back, giving your opponents much less time to react.
2. Momentum. The bird coming towards you has more momentum towards you the sooner you take it. Meaning that when you hit it, you can "borrow" its momentum to reverse direction towards your opponents, thus making it more powerful and also saving you energy at the same time.
3. Shuttle angle. The earlier you take the bird means that the cork is aimed more upwards than downwards. The former makes it easier to time and transfer power properly, while the latter is easier to mishit as the feather skirt gets in the way.
simple. just hit everything as early as possible. (which may or may not be as high as possible). there, done.The only time you delay is to fake out your opponent. you're tired. you thought it was out but not.
You should stay back and try to smash it because that is the high percentage shot to do, going forward near the net and try to jump up to intercept the shot is low percentage and high chance you will miss the birdie .
Originally Posted by pcll99
thanks everyone. i was speaking generally.
let's say there is a lift by the opponent. I may be able to rush up to the net and hit it early (but just may be.) Or, I may stay at the back and smash it at the rear. what should i do?