Jason Richardson won two NBA slam-dunk contests in 2002 and 2003. His between-the legs-dunk in 2003 three was one of the most explosive, athletic slams in the history of the contest. In the preseason when the Sixers entertained the Celtics, the then 31-year old Richardson showed he still had such hops with a one-handed slam in transition. He added a 360 dunk to his Sixers highlight reel in a game against the Bucks. Unfortunately, that Nov. 13 dunk against Milwaukee may be the last above-the-rim experience for the 6-6 guard. Richardson confirmed on Friday morning that he will undergo season-ending knee surgery next week to repair a hole in the cartilage of his left knee. “I have a hole the size of a quarter in my knee that is required to get fixed,” Richardson said. “It is going to be a long process to getting back on the court. I mean it’ll take anywhere between nine and 12 months. “What they do is take a cartilage graft from someone else and pretty much implant it in there. I think the reason it takes so long to heal is that it needs to take and that is why it is such a long recovery time.”