Jason Vargas and his Change-up

Through three starts, Jason Vargas has performed noticeably better than last season, despite having pretty much the exact same stuff. Through 18.1 innings, Vargas currently sports a FIP of 3.19, compared to last season’s 5.07 FIP and a career FIP of 4.95. How is this happening, and is it sustainable?

The 2010 version of Jason Vargas is simultaneously posting the highest K/9 and lowest BB/9 rates of his career (7.85 and 1.47 respectively). This, of course, has led to his incredible 5.33 K/BB ratio. Over the last five seasons, the league average K/BB rate has been almost exactly 2.00. Vargas’ current career high K/BB rate is 2.25 (from his 2009 Mariners campaign). Initially, I assumed that Vargas’ insanely high K/BB rate had more to do with small sample size than anything else and that it was completely unsustainable. While I still think that his current K/BB ratio and FIP are unsustainable, there are a couple of interesting changes taking place in Vargas’ approach to pitching that have made me think there’s something more to his success than just small sample size.

Before I get to that, however, I’d like to point out some other interesting Jason Vargas tidbits:

*Vargas’ BABIP of .282 this season is not outside the norm and suggests that he’s not getting lucky with defensive plays behind him.

*A very low 14.8% line drive rate, along with a very low 7.7 HR/FB%, is almost definitely unsustainable. The last three seasons, Vargas has posted HR/FB% rates of 11.7, 14.8, and 12.7. Vargas has been getting a tad lucky with the amount of home runs he’s allowed this season, and this more than anything else will lead to a higher FIP as the season progresses.

*His groundball rate continues to be significantly higher in Seattle than at any point of his career. In 2009 and 2010, Vargas has posted groundball rates of 36.6 and 37.0 percent. In 2005 and 2006 with the Marlins (the only other significant time he’s spent in the majors), his groundball rates were 31.4 and 32.0 percent. I don’t see any reason for this not to continue, and this increase in groundballs will only help him considering how good Seattle’s infield is defensively.

The biggest difference between 2010 Vargas and Vargas in any other year, however, is his drastic increase in percentage of change-ups thrown over his career average. When I say drastic, I mean DRASTIC. Throughout his career, about 19.8 percent of Vargas’ pitches thrown have been change-ups. He’s never had a rate higher than 20.1 percent. Vargas’ rate this year? 29.9 percent. Through three starts this season, Vargas is throwing significantly more change-ups than he has at any other time in his career. This 10 percent increase in change-ups thrown has come with a 10 percent decrease in fastballs thrown (58.3 percent this year vs. 68.9 percent last year and 67.3 percent for his career). He still throws the same amount of sliders and curveballs, and the velocities of all his pitches seem to be about the same as normal, so this leads me to believe that Vargas has simply “changed” his approach to pitching over the off-season: more change-ups, fewer fastballs.

And guess what? It’s working.

Vargas has been far more deceptive with his pitches this year than he has at any other point in his career. Batters have swung at 32.7 percent of his pitches thrown outside the strike zone this season (O-Swing%). The league average O-Swing% is 26.7. Vargas’ career O-Swing% is 23.8 (last season it was 27.7). His swinging strike percentage is at 9.2 – about a percent above both the league average (8.3) and his career average (8.2). If he can sustain his apparent increase in deception, which I believe to be brought on by his increase in change-ups, then his increase in swinging strikes and O-Swing% should be at least somewhat sustained as well.

I don’t believe that Vargas can keep up his strikeout-to-walk ratio or his low LD% and FB/HR%, but if his newfound confidence in his change-up continues to show results, then there is no reason to think that he won’t be a solid starter for the Mariners all season long. Ian Snell and Ryan Rowland-Smith better watch their backs, because the way those two have been pitching (badly), and the way Vargas and Doug Fister have been pitching (unbadly), when Cliff Lee returns on April 30, it will be either Snell or Hyphen throwing out of the pen.