I'm not sure if Curt Schilling will be the stopper that he was last season when he returns for the Red Sox. I think his ankle has undergone too much trauma, and he had some peripheral stats already falling from his established levels last season. Let's take a look at his PECOTA projection for 2005:
ERA: 3.70
IP: 208.3
K/9: 7.4
BB/9: 1.5
HR/9: 1.1
H/9: 8.8
VORP: 56.0
Breakout Rate: 12.2%
Improve Rate: 26.0%
Collapse Rate: 31.9%
Attrition Rate: 0.0%
His collapse rate is extremely high, and that just might be the one that shows up when he comes back. I expect him to be a pretty good pitcher for the rest of the season, but I think Matt Clement will be the Sox ace statistically, if not in name like Schill. Just know that Schilling is probably on his way to the Hall of Fame if he can finish up his contract with the Red Sox in respectable fashion.
Schilling
Career WARP3: 93.0
Peak WARP: 42.8
JAWS: 67.9
PRAR: 1013
PRAA: 306
Average Hall of Fame Pitcher
Career WARP3: 95.1
Peak WARP: 43.6
JAWS: 69.4
PRAR: 964
PRAA: 205
Well look at that. WARP3 is Wins Above Replacement Level, adjusted for all-time and for playing time. Peak WARP is the five best consecutive seasons of WARP3 added together. JAWS is [(Career WARP3 + Peak WARP) / 2]. PRAR is Pitching Runs Above Replacement, a good secondary indicator of career value. PRAA is Pitching Runs Above Average, a good secondary indicator of peak value. As you can see, Schilling stacks up nicely, and as long as he can perform well for a year or two down the road he should be a lock, thanks to the most famous sock on the planet and some amazing 2001 World Series performances behind him already.