Froch had trouble with grove's speed, he would be a punching bag in there against the much faster south paw volume puncher calzaghe. He would get lit up and probably stopped rather easily. It's a horrible style match up for froch. And calzaghe would have ate that punch like a cupcake.
I love how Calzaghe fans try to remind us he existed whenever Froch fights. What's funnier however, is that Calzaghe didn't fight(something he's known for) Froch and thought Manfredo Jr. was more worth the time and effort.
yes, you would expect calzaghe to outpoint froch. still, froch has the power to stop calzaghe. boxing is never 100% certain. calzaghe didn't want it
Joe probably would have beaten Froch by a wide decision. That said, Froch has shown himself to be much better than Joe about stepping up to serious challenges.
Instead of retire, he simply dropped the belt. Nothing to worry about there if you're Calzaghe because no fan will even notice or discuss why the belt was dropped.