Which attacks produce guard break?
214+K (+4 on block)
P,P,4+P, K (+2 on block)
6+P, P (-2 on block?)
4+P, K (-4 on block?)
sidestep+K (-4 on block?)
P, P, 6+P, P (+8 on block at full charge)
Anything else? Well we have 1+P+K of course, but it's harder to use it effectively at close range...