Julio Cesar Chavez is probably the best fighter who knew how to cut off the ring...

have you ever heard of a fighter named roberto duran

 

i think cotto was cutting off his own ring by going against the ropes, which margo capitalized on beautifully....but margo aint good at cutting off the ring :nono
if you notice, cotto was frustrating margo when he would go in and out, margo was basically just walking him down with a plan to bruise him up and tire him out ....but if you watch a prime chavez, you will see what cutting off the ring really means :good

 

Chavez was pretty much the quintessential pressure fighter. Not the very best at flat out pressuring or in-fighting, but the most methodical in terms of cutting off the ring, getting work in, and slowing the opponent down for the late rounds where he'd take advantage and finish them off. He had 15 round stamina as well.