I just watched the Wang Hao Ma Long match a few times.
If you watch, over and over again, Wang Hao is using that reverse serve to Ma Long's forehand and keeping it short and really low. Ma Long cannot attack it so he is trying to push it. But his push with his forehand is not so good and he really cannot handle that reverse serve. He pops so many of them up. A lot of the time when Ma Long serves Wang Hao pushes really short to Ma Long's forehand too. Same basic result although Ma Long is better at pushing against a push than against that reverse serve. And then, Ma Long starts trying to open on those balls that are too short for him to take a big swing on his forehand and he really misses a lot of those.
That is tactics.
That is keeping those pushes short, low and at a place where Ma Long is temped to take them with his forehand but actually cannot. When they go to his backhand he is okay at handling them because he can actually take them over the table. But, he is really looking to get his forehand off and neglecting the opportunities to open with his backhand.
I also watched the match from the Finals of the Kuwait Open where Zhang Jike beat Ma Long 4-1. Zhang Jike does the same exact thing to Ma Long as what Wang Hao does. The one difference I see in that match, when Ma Long does get off his huge forehand to open while close to the table, Zhang Jike is usually there and responds with a counter loop. It is a very short stroke but it has all of Ma Long's power and he gives it right back to Ma Long, who is usually not ready for his giant forehand to come back. He is often not even set for a next shot when Zhang Jike rips Ma Long's forehand back.
Here: have a look:
Before this match, I had never seen Zhang Jike have a real answer to Ma Long's relentless attack. My money says he watched what Wang Hao has done and learned to keep those serves extra short to Ma Long's forehand and realized how much trouble he actually has with the reverse spin when he is trying to take it with his forehand.
This comes from that practice Liu Gouliang has them do where they are trying to serve under the racket and get the ball to land really close to the net.
And it also comes from learning to push really short where you take the ball right off the bounce and just touch it over the net so it barely gets over and does not bounce very high at all. Very hard to do and you must have really good touch, footwork and anticipation to do it consistently in a match. But that is what Wang Hao did to control the game and keep Ma Long from launching his huge forehand attacks.
