At the expense of one power stock, you can choose to cancel your guard into a roll by pressing Light Punch + Light Kick. Unlike normal rolls this roll is completely invincible from the very start to the very end. This technique is much safer than a Guard Cancel Blowback, as it cannot be countered at all. Even if your opponent anticipates it, the best he can do is set up a meaty as soon as you recover from the roll.
By default, you roll backwards, but if you keep forward pressed while performing a Guard Cancel roll you will roll forward.
Strategy Corner If you anticipate that your opponent is going to cancel into quite a slow move, you can decide to Guard Cancel Roll his attack, and you will recover from the roll while your opponent is still in the animation of the attack he cancelled into. This makes your opponent extremely vulnerable to punishment.