So what can be attributed to this statistical and performance slide? Well to start, Halladay went on the DL for the first time since 2009 with a strained latissimus dorsi. Even yesterday, after his seven run shellacking, Doc admitted he still is not 100% healthy. In addition, Halladay has seen a steady decline in his fastball, cutter velocity, and curveball velocity. As the case with a velocity decline, pitchers usually have less margin for error since hitters are able to adjust easier and punish mistakes. This is evidenced not only by his lackluster results but also a higher contact percentage rate against each of these pitches. However, pitchers with decreased velocity can sometimes face little performance tradeoff if their control is maintained or improved. Yet, as mentioned earlier, that is not the case as Halladay is walking more batters at a higher rate (5.3 BB%) since 2004. Of course this rate remains well above the league average of 8.5 BB%, but this still is not typical "Doc" and certainly has had some influence on his poor performance this season.
So how much of this is attributable to injury, old-age, or bad luck. His BABIP of .299 this year is right at league average so bad luck on balls in play really is not a factor. However, his left on base percentage is well below his rate of the past couple of years (averaged a 78.58 LOB% from 2008-2011) and below league average (72%) so some bad luck may be the case here. However, most of the data does not point to regression to the mean which signifies that it is unlikely we will ever see Doc and his surgical precision again. Not to mean that he cannot remain a valuable middle of the rotation pitcher in the coming years (still has a very solid 3.67 FIP this season), but his times as a bona-fide ace are probably numbered.
With only 1 guaranteed year remaining on his contract and a recent injury history, Halladay's 2013 campaign will be a pivotal stage in his career. At this point, Halladay is probably a borderline Hall of Fame candidate needing several more productive seasons to ensure Cooperstown immortality. In addition, despite an impeccable and storied resume, Halladay will face his hardest test in the coming off season, when he will be doubted for the first time since his first career revival in 2000 with then minor league pitching coach Mel Queen. Unfortunately, Queen has since passed and Halladay is much different from the immature 23 year old kid that completely changed the path of his baseball future under Queen's tutelage. This time, Doc will be the one under the knife.