Short game is all the stuff over the table that keeps your opponent from attacking or making an opening attack that is strong enough to hurt you. And short game is also your ability to attack anything that is over the table regardless of where it is.
If your short game is good enough to keep your opponent from being able to launch an attack then you have put him at a huge disadvantage. If your short game is good enough that, what ever your opponent gives you, you can attack it in a way that exploits your opponent's weaknesses or wins you the point outright, then, you have a huge advantage.
Part of short game is how low you can keep your pushes. The placement is of course an important part as well. But, if you can make a push that has a very low bounce, and is very short, for instance, say you push and the top of the bounce of your push is half the hight of the net and the first bounce is 4 inches past the net and it would bounce several times before reaching the end of the table, and that push is right in the center of the table, that is a very hard ball to attack. Short game has everything to do with touch and control. Now, say your opponent gives you that push I just described, or a serve with similar hight, spin and placement, and you can loop that with good pace and heavy spin from your backhand, to the middle, the deep forehand or the deep backhand, that is going to be hard for the opponent to handle.
Go and watch how Zhang Jike loops over the table with his backhand. His opponents rarely can tell where he is about to go with his shots because he is so good at that over the table backhand. Part of that, for him is also that his footwork is amazing. You really cannot have a good short game without good footwork.
Looping is easy compared to the touch of a really high level short game. And looping underspin if it comes past the edge of the table is easy. If you are forced to do it when the ball is short, low and over the table, it is not so easy.
