When you look at fighters who gave Mayweather trouble at some point in the fight, it was usually smaller guys who were quick and could counter punch really well.. castillo and zab judah come to mind.. zab fought mayweather well in the first half of the fight until floyd adapted..

i see this fight as really boring at the beginning, where floyd basically pot shots to get marquez REALLY frustrated so that marquez opens up more and throws more punches at which point mayweather COULD get caught, but will play it even more safe and just try to land clean shots..

IF this fight is close going into the 8-9th round then i think we will see a great finish where mayweather will HAVE to open up and fight..