Koji Uehara: O’s Ace

Baltimore Orioles fans must live a peculiar existence these days, with one eye on the Jones’ and Markakis’ of the major league squad and the other eye fixed squarely on the minor league box scores, checking up on the Wieters’, Tillman’s and Matusz’s of the system.

It would be difficult to fault anyone for taking such an approach. Residing in baseball’s most challenging division, the O’s currently sit at 16-21, with a -30 run differential that ranks dead last in the American League. The main culprit has been the starting rotation. Calling upon fellows named “Eaton” and “Hendrickson”, Baltimore has gotten a collective 5.41 FIP from its starters, which ranks ahead of only the homer-happy Phillies group.

However, not all is bleak. The Orioles appear to have landed themselves a quality starter on the free agent market this past winter in Koji Uehara.

A Japanese import, Uehara came stateside with the reputation for pounding the strike zone. He’s done just that, with 7 unintentional free passes in 42.2 innings pitched (1.48 BB/9). The 34 year-old right-hander has been as adept as any starter in terms of getting ahead 0-1 or inducing contact on the first pitch. His 69.4 First-Pitch Strike Percentage is significantly above the 57.7% major league average, and ranks behind only Arizona’s Dan Haren (71.6%) among all starters.

While no one will mistake Uehara for a power pitcher, he’s no weakling out there either. The former Yomiuri Giant has managed to strike out 6.75 batters per nine innings, giving him a sterling 4.57 K/BB ratio that places 7th among starters. Uehara’s repertoire is expansive: in addition to an 87.2 MPH fastball (used 56.6% of the time), he unleashes an 82 MPH cutter (6.7%) and a 66.1 MPH curveball (81.7 MPH). Of course, his bread-and-butter offering is a dastardly 79.3 MPH splitter, a strikeout pitch thrown 32.5% of the time (our pitch data also shows him throwing a few changeups, but those are likely splitters as well).

That splitter offers great contrast to his rather modest heater. Uehara’s fastball actually has a significant amount of vertical movement for a pitch thrown at such velocity, with 12.2 inches of vertical break compared to a pitch thrown without spin. His splitter, in contrast, has 6.3 inches of vertical movement (Pitch F/X classifies it as a changeup, but most everyone refers to it as a splitter).

Take a look at this release point chart from Uehara’s last start against the Yankees, on May 10th. Notice how his release points on the fastball and splitter (called a changeup here) overlap:

Now, note the pronounced difference between Uehara’s fastball and splitter, in terms of vertical movement (focus on the green and orange dots):

The two pitches come out of a similar arm slot, with about a 7 MPH difference in velocity. Yet, one drops a half-foot more than the other at the last moment. That’s deceptive, and has likely contributed to Uehara garnering a good deal of swings on outside pitches. His Outside-Swing Percentage sits at 30.8, above the 24.4% MLB average.

Uehara does have one flaw. Namely, his penchant for putting the ball in the air. As one might expect from a guy working up in the zone with mid-to-high-80’s cheddar, Uehara has posted one of the lowest groundball rates in the big leagues. His 26.3% mark is second only to Ted Lilly (23.6%). That flyball-centric approach has led to 1.27 home runs per nine innings.

Koji Uehara did not venture to the majors with near the same degree of fanfare as some recent Japanese players, but he has acclimated himself about as well as one could have hoped for. With a 4.04 FIP and a nasty splitter, Uehara will hold the fort until Tillman, Matusz, Arrieta and company are ready for prime time.