Of the recent greats to retire, some have retired with their capabilities intact; some while still credible players; some as an embarassment.
The first group includes Scott Stevens and Patrick Roy. Patrick Roy retired after one of his best seasons statistically and shortly after a championship. Scott Stevens was still knocking players silly and winning Cups when he bowed out.
In the second group, I think mostly of Wayne Gretzky. He wasn’t scoring 100 points anymore, and he was noticably slower, but he was still a credible player. He picked his spot probably just at the right time. Al Macinnis fits here too. He wasn’t the dominant force that turned around a 3-1 series against Phoenix in the Blues favor in 1999, but his departure wasn’t addition by subtraction either.
In the last group, you find Grant Fuhr, who, I believe, was ironically a Calgary Flame when he left. You find Paul Coffey, who went from being the best to being a journeyman player. And, most recently, Mark Messier.
If not for the ass washings he received every game from Sam Rosen, he would have appeared to be a dud player in each game. Press rumors had him demanding second or first line minutes, which, on the Rangers, may have been proper–but, he wasn’t that caliber of a player anymore.