I think for this one we have to look at Calzaghe's comment himself. He himself has said that he has only 3 more fights before he retires, so that would only take him to 22 succesful fights, and that is if he stays at SMW, where he was struggling at the weight a few years ago. Even though more recently he is more comfortable at the weight, can anyone really stay at the same weight they started out as 15 years before? It would be a hard task for him, and I don't see him having the desire to do it. If he beats Kessler, and unifies the division after Bika, that will be one massive achievement, and then a victory to win a Light-Heavy belt is really the extent of his ambition.