Not often do you see a 33 year old pitcher with a winning record and a sub 4.00 ERA retire, but it's been clear for about a year or better that Matt had lost his edge. I think he really lost it after the shoulder surgery even though the bullpen plan the Cards put him through was a really good idea. I remember when he came up with the Cardinals and Tony LaRussa called him The Real Deal, which he was for a number of years. Injure your elbow and have Tommy John surgery and you come back a better pitcher. Injure your shoulder and it's a 50/50 shot of returning to form. Matt never really came up on the plus side of those odds.