Hi,
Indonesia, humm. Nice place, I hear.
So where exactly are you, then?

Anyway, fat shots.
They are shots where you hit the ground (or mat) before the ball.
Why they're called fat, I don't know, but that's the term everyone uses, so that's what I use also. :¬}

From your other thread about hitting the top of the ball, I think you're not having any fat shot problems. But don't imagine that they can't appear. Keep checking occasionally that your not making those thud-clicks on the mats.

So your topping shots, not hitting them fat. Seems that you need to concentrate on not lifting your head, as I mentioned in the other thread.

Could also be instead that you're slightly off balance with too much weight on your heels at address. When addressing the ball, you should have your weight evenly distributed between your toes and heels, and more on the inside of the soles of your feet than the outside. I find it helps to adjust my stance/distance from the ball until I feel my weight under my foot arches.
Another way to think about front-back balance is that it should be no easier for someone to push you forwards from behind than backwards from infront.

If you check your balance like this and take care not to lift your head, then that should stop you topping the ball.

Finally, make sure that the ball is not too far forward in your stance, i.e. too much in front of your left foot, and not too far away from you so that you're having to over stretch.

Tom