Brock Lesnar doesn't just stop offense. He stops all movement from underneath. He keeps hips from swiveling and shoulders pinned to the mat. He uses a combination of size to blanket his opponent, strength to control them and natural athletic power to throw short yet crushing strikes in tight range. The secret to Bruce Lee's "one inch punch" was just physics: can you generate enough force in the one inch margin to knock a man off of his feet? For Lesnar, it's a similar circumstance. Even with Mir's head cradled in one arm and the other arm hand fighting with Mir, Lesnar needs only a few inches to land a substantive punch that won't turn the lights out, but quickly accumulates the punishment. Mir previously criticized Lesnar's ground and pound for not creating enough distance when he strikes, but if your power is so massive that you require nothing more than a marginal space, what can one reasonably do to defend?
"I'm like the superhero coming in with the anti-bullsh*t." - Nick Diaz