In 2014 Tanner Roark had a 2.85 ERA, 1.09 WHIP and 15 victories. That effort compares very favorably to the seasons posted by Zack Greinke (2.71 ERA, 1.15 WHIP and 17 wins) and Julio Teheran (2.89 ERA, 1.08 WHIP and 14 wins). So why on earth would I be telling you to stay away from Roark? Is your interest piqued?
Roark struck out 6.25 batters per nine innings in 2014. Not only was that mark a half batter below his rookie rate from 2013, it was also a batter and a half below the big league average of 7.73. The result for Roark was 138 Ks in 198.2 innings pitched. That's one less strikeout that Jorge De La Rosa and seven less than Dan Haren. That ain't good.
Roark generated a 50 percent ground ball rate as a rookie. In year two, that mark dropped all the way down to 41 percent. Roark therefore went from an elite 1.95 GB/FB ratio down to a league average mark of 1.09 in 2014. During his minor league career, that mark was 1.21 which seems to signify that the effort we saw in '14 is more likely to be repeated than the elite '13 mark.
Roark had an elite 79.8 left on base percentage mark as a rookie. He posted a 79.3 percent mark in 2014. Obviously he's just that good. Well, not quite. As the Pitching Targets article points out, it's virtually impossible to sustain a level that is this high year after year. Just not happening in 2015 folks.
So in Roark we have a pitcher with a sub par K-rate, a moderate GB/FB ratio and a left on base percentage mark that is simply unsustainable. Let's be even more aggressive with our analysis.
Raw ERA is a poor way to understand pitcher performance (more on that in a future article). Hopefully we can all agree with that at this point. For his career, Roark owns a 2.57 ERA over 252.1 innings. However, as briefly noted, his skills don't support that mark. Moreover, two other measures emphatically point this out. SIERA and xFIP are reported the same way as ERA, meaning, they produce marks directly akin to what you expect with ERA. Not getting all technical, SIERA and xFIP remove some of the "white noise" with ERA and speak more directly to what the pitcher has done on the field. Those two marks are 3.81 (SIERA) and 3.69 (xFIP ), more than a run above Roark's raw ERA.
Bottom line with Roark is that he will be over-drafted. His ERA will most likely rise, perhaps significantly, and he's nothing more than a moderate strikeout arm. It's always tough to expect youngsters to repeat 15 win seasons as well. At the right price Roark is worth adding, but most likely someone in your league will take him earlier than he/she should. That's right, we know that ladies play fantasy sports too. Represent ladies.
NOTE: The Nationals signing of Max Scherzer makes it likely that Roark will begin the year as the Nationals long-man out of the bullpen crushing his mixed league value.