do people grab break in street fighter games on reaction? or do they just know the situations in which people try to grab?
also if anyone wants to play an awesome multiplayer platformer, try Rayman Origins. That game is ****ing amazing.
It's mostly about recognizing the situation. Also, if you see someone walking straight up to you past jab range, it's 80% likely to be a grab. The first and maybe second grabs are free, but after that you should probably have an idea of how the player is integrating them and be able to react to the situation. Grab range is pretty bad in SFxTK, so it's usually even easier to see the grabs coming.
Grab situations:
Walk-up Grab - You've been mind****ed
Jab x n > Grab
Empty Jump > Grab
Blocked Jumpin > Grab
Blocked Jumpin > Jab x n > Grab
Meaty Grab on Wakeup
Most of these are beaten by simple jabs, but you'd be running the risk of getting counterhit. As long as you can play a decent footsie and spacing game, there aren't really any ways for you to get grabbed in other situations.
Also, I don't think my brakes ever gave out at a Smash tournament. There was one time I didn't have brakes coming home from work, though. That was fun.