Lacy is cut prone ... it wasn't because of anything that Calzaghe did ... Every since he was an amateur is was ruled that Lacy would have trouble with boxers as a pro. They evaluate amatuer olympians and give an assessment on how they would fair as pros. Calzaghe showed against Hopkins - that he isn't that good technically and relys alot of his speed and endurance. He can't throw straight punches and doesn't have the ability to defend straight punches. He opens himself up for punches when throwing his windmill combonations. Given the right opponent Calzaghe can lose and lose bad ... he showed that in the first round getting over anxious and getting a flash knockdown. He also got hurt at the end of a round in the middle of the fight ... he came at Hopkins with 8 punch flurry, nothing landed, and at the end of his flurry, he got caught with a left hook that had him stunned. He also keeps his chin up when he's throwing and squares up ...
If Joe was as vulnerable as you seem to suggest he wouldn't be undefeated at this late stage in his career. He has phenomenol, catlike reflexes and so can fight unorthodox and not pay the price mere mortals pay. He gets away with alot just cause he can.
He throws punches like a girl (windmill punches) ... he squares up when throwing his combonations ... often times wasting punches, because even though his punch output is high ... he's not landing anything effective if at all. He's fast and has good reflexes, but he's very hittable and has a hyper over anxious style. I think a fighter with a decent work rate in the championship rounds and throws more than one punch at a time w/ equal speed to Calzaghe ... they can beat him. His resume has a few names on it, but he has under 10 former/current champions on his resume. He also has some fillers who never accomplished anything in boxing. he's never had to tighten up because he always had the physical advantages over his oppenents. Never was about boxing ... it was always about him overwhelming guys with his speed and workrate. The lack of former champions show that his lack of elite level competition on his resume ... you catch a guy thats just as fast and throws straight punches ... he can get knocked out. Calzaghe's good but he's not that good ... he does punch like a girl and he's very bad technically ... and his balance is terrible.
O.K. But what about that southpaw jab? Everything was in the toilet by the end of round 4 and THEN Joe starts backing Hops up with beautiful, precision jabs. At one point he actually started running after Bernard to try and score the second jab as Hopkins wanted no part of it. Joe has got boxing skills to go along with that crazy speed and reflexes but his punch delivery seems to annoy people.
Given he's been down three times, you can't say that. It clearly works for him. He might not have the most effective footwork if you're a traditionalist, but it works.