"no direction" = no up nor down "any" = can be up, can be down, can be no nor down, but it has less priority than "up" or "down", so you can assign another strike on the "up" or "down"
That is really compatible with a heating problem...
You can check your monitor frequency in your Windows settings, or in-game, you can set Settings -> Video -> Exclusive Fullscreen and then select 60 hz (with V-Sync in the Advanced options if you had turned it off).
Hello, 1) Any/No direction is just about the detection of the selected strike ; it'll change soon, and get more simple to assign your strike ; it doesn't change the result of the topspin strike 2) The advantage of having the normal strike on B1 and the topspin strike on B1+down (or anything similar)...