23 September 2014

A Statistical Look at Previous O's Rotations Since Baltimore's Last AL East Crown

By most accounts, the Orioles' starting rotation has been a pleasant surprise in 2014. They've been somewhat fortunate, but all starters not named Ubaldo Jimenez have been anywhere from good to pretty good. The rotation has received a huge assist from stellar team defense, which has enabled O's starters to strand runners and prevent runs.

As noted in the link above, O's starters do not fare well when analyzing their performances by various metrics that typically predict success. They aren't great at racking up strikeouts; they aren't particularly adept at limiting walks (besides Wei-Yin Chen); they don't induce a bunch of grounders; they don't routinely pitch more than six innings per start, etc. You get the idea. O's starters have a 3.62 ERA (sixth in the American League) but a FIP of just 4.32 (14th in the AL).

According to FanGraphs' version of wins above replacement, the O's rotation ranks 14th in the AL. Here's how O's rotations have finished in terms of fWAR since 1997, when they last won the AL East.

Starters fWAR (AL ranks) 

1997: 14.4 (4th)
1998: 14.5 (5th)
1999: 10.0 (10th)
2000: 12.1 (9th)
2001: 7.2 (t-12th)
2002: 6.1 (14th)
2003: 8.2 (10th)
2004: 10.3 (10th)
2005: 9.9 (11th)
2006: 9.8 (11th)
2007: 10.2 (t-11th)
2008: 4.3 (14th)
2009: 6.5 (14th)
2010: 7.6 (13th)
2011: 5.0 (14th)
2012: 9.4 (8th)
2013: 7.0 (14th)*
2014: 8.9 (14th)

*The Houston Astros joined the AL West as the league's 15th team.

That 1997 rotation included Mike Mussina, Scott Erickson, Jimmy Key, and Scott Kamieniecki. In 1998, it consisted of Mussina, Erickson, Doug Drabek, Sidney Ponson, Juan Guzman, and lesser seasons from Key and Kamieniecki. Mussina was excellent nearly every season for the Orioles, while those two seasons may have been the best of Erickson's career.

O's rotations haven't finished higher than eighth in the AL in fWAR since 1998. That's a long time. But fWAR is based on FIP, meaning a heavy emphasis on strikeouts, walks, and homers. Sometimes pitchers are able to outpitch their FIP over a decent amount of time. Chris Tillman and Miguel Gonzalez have been doing so for the last few seasons. Of all pitchers with at least 150 innings pitched this season, Gonzalez's ERA-FIP of -1.64 is the highest (or lowest?) in the majors. At -0.83, Tillman is seventh. From 2012 to 2014, of all pitchers with at least 300 innings, Gonzalez is still the leader (-1.13). Tillman (-0.87) is third.

Ranked by a simpler statistic -- Runs Allowed, which takes into account all earned and unearned runs -- the O's have fared much better (in 2014, at least).

Runs Allowed per game by starting pitchers (AL ranks)

1997: 4.20 (1st)
1998: 4.85 (7th)
1999: 5.03 (3rd)
2000: 5.64 (12th)
2001: 5.12 (10th)
2002: 4.77 (7th)
2003: 5.03 (9th)
2004: 5.12 (9th)
2005: 4.94 (10th)
2006: 5.55 (13th)
2007: 5.36 (13th)
2008: 5.40 (13th)
2009: 5.41 (14th)
2010: 4.85 (13th)
2011: 5.31 (14th)
2012: 4.35 (8th)
2013: 4.38 (9th)
2014: 3.65 (3rd)

First, note the significant decline in scoring. Second, see the improvement for the O's rotation. Obviously they rank much higher when defense isn't eliminated from the equation. It's been 15 years since they rated this highly in the AL at preventing runs.

Maybe the Orioles have some starting pitchers who are underrated. Or maybe the Orioles realized that it's easier to make a pitching staff look better as a whole when defenders behind them make more plays. Or, most likely, both are true to some extent.

Photo via Keith Allison

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