Topspin and Short Serve -- > 3er Ball Problems.

Dear Alois,

Hi, Good morning!

I'm having some problem with my 3rd ball attack when I serve short and with topspin.

The ball looks easy to attack because it bounces a lot, so I hit it, but most of the time it go into the net.

The problem is that it came with a lot of backspin and near to the net. All the time I move fast and i try to make a shot with lot topspin, but the ball go to the net 50 % of the time. I think that Im doing the stroke very horizontal.

But how can I do to make the stroke more vertical if the ball bounce is near the net?

Could you give me an advice?

Thank in advance

Gabriel.