Tom Szczerbowski-USA TODAY Sports
Georges St-Pierre is a big, strong fighter with great wrestling and top control. The Diaz brothers, as skilled as they are, have always been lacking in the wrestling department.
For example, look at Rory MacDonald vs. Nick's brother Nate Diaz. MacDonald, a training partner of St-Pierre, rag-dolled Nate Diaz for the duration of their UFC 129 fight in April 2011.
GSP vs. Nick Diaz will look exactly the same. St-Pierre will overpower and out-wrestle Diaz en route to a decision.
Even if you give Diaz the advantage in striking and jiu-jitsu, St-Pierre's advantage in wrestling is so great that it will very likely negate Diaz's advantages in these areas.
St-Pierre will take him down to avoid the striking, and will land light ground-and-pound while smothering Diaz to keep the fight from being stood up.
This will leave a bad taste in the mouths of MMA fans.