Short ball off opponents lob

I often see players play short balls off a lob, but I often see Ma Lin play a short ball off of an opponents topspin far from the table. Any tips on playing this sort of shot.

Hi John,

Take a look at the lesson we have on this topic.  I think it will be a good guide for you.

The lesson is Drop Shot off a Lob.  Take a look and let me know if it helps.