downside to using the mechanic aside from having to correctly guess what the opponent will do before the roller becomes vulnerable. In the final major patch, dubbed the :2013 edition", the underwent two major changes.
A hurtbox now appears on the rolling character during the final 7 frames of the attack. The rolling character can still block when this hurtbox appears, It needs to be emphasized that the rolling characters can not perform any other actions than block during these 7 frames.
The rolling character gets a throwable hurtbox during the final 10 frames of the attack. Unlike the strike hurtbox the defending character can not Tech the throw. This means that an opponent that correctly anticipates the roll can get a guaranteed throw. Command Grabs and Super Art throws also can not be defended against.
These changes (among others) were done to speed the game up and prevent Time Overs, a mechanic that plagued the game throughout it's previous history.
Tactics
Poison correctly anticipating that Ling Xiaoyu will Roll after a sweep, enabling Poison to grab Xiaoyu with Frankensteiner afterwards.
Rolls are meant to be a defensive mechanic. Rolling allows players to avoid offense heavy Cross Ups and Option Selects, among other tactics. Care has to be taken as opponents that correctly anticipate a roll escape attempt, as they can be thrown and end up taking more damage or be forced to deal with a mixup at frame disadvantage. Some throws like Uki Yami place the opponent at a similar position they initially rolled from.
Rolls forces pressure in Street Fighter X Tekken to be applied differently than in Street Fighter IV and to a lesser extent Street Fighter V as they are made to excape the intese Wakeup game "IV" is known for. Players are encouraged to find compromises that accounts for an opponent rolling off knockdowns, or finding set ups that do not matter if their opponent rolls. It should be noted that knockdown setups still work in "X Tekken" but should only be applied sparringly after discouraging the opponent from rolling.
Trivia
The Back Tech mechanic from Street Fighter V could possibly have been inspired by this mechanic
Gallery
Here Kuma grabs Xiaoyu with a Command Grab, a tactic that is guaranteed to work against Rolling
Ibuki performing a mixup on Ling Xiaoyu after baiting her to Roll. This takes advantage of the 7 frames the opponent can not perform reversals on.
Ibuki baiting Ling Xiaoyu to roll, since Xiaoyu rolls in the corner it is easy to throw her with Yamikazura
