Bartolo Colon gets the start tonight, his first in a Boston uniform, so I thought it might be worthwhile to do some research on him.

Colon was a very good pitcher prior to 2006. From 1998 to 2005, he was a workhorse, pitching over 200 innings every year except 2000 (188 IP). His ERA was over 4 only twice in that period: 4.01 in '01, and 5.01 in '04. This reign of dominance culminated with him winning the Cy Young Award in 2005, after going 21-8 with a 3.48 ERA.

Then things fell apart. Colon spent most of '06 on the DL with inflammation of the right shoulder, having torn his rotator cuff in the '05 playoffs. He only pitched 56.1 innings in '06, and 99.1 the following year. '06 and '07 were Colon's worst years for ERA (5.11, 6.34 respectively), aside from his rookie season.

Looking more closely at his last two years (i.e. using Excel), Colon pitched badly in several ways. He had fewer strikeouts: his average Ks per 9 innings in 2006 and 2007 was 5.9, versus an average of 7.2 Ks per 9 from 1998 to 2005 (his dominant era). Colon also allowed more home runs, at a rate of 1.56 per 9 IP, as opposed to 1.04 / 9 in his dominant era. Colon walked proportionally fewer batters in 06/07 than in 98-05 (2.2 BB / 9 to 3.1 BB / 9), but this did not make up for his increased HR and decreased strikeouts.

Colon has lost velocity since his Cy years, but he can still throw pretty hard.  According to Dave Ricci of MLB.com he threw as hard as 95 mph on 5/15 in Pawtucket. His scouting report on Soxprospects.com lists his pitches before the injuries as the four-seamer, "an excellent sinker, a decent slider, and an average changeup."

So what can we expect from Colon? In the long-term, everyone will have died, and a few seasons of baseball won't matter. In the short-term, I expect him to pitch decently against the Royals: 6 IP, 3 R or fewer. In the slightly longer term, I'm guessing we'll see numbers somewhere in between those of 06/07 and those of his earlier dominant stretch.

How do you think Colon will perform for the Sox? And did you find this diary interesting? Let me know in the comments.

Sources / More Colon material to digest:

http://www.soxprospects.com/players/colon-bartolo.htm

http://www.baseball-reference.com/c/colonba01.shtml

http://boston.redsox.mlb.com/news/article.jsp?ymd=20080515&content_id=2706849&vkey=news_bos&fext=.jsp&c_id=bos