At this point, the AL East title is a foregone conclusion for the Baltimore Orioles. MLB.com’s playoff odds (via Baseball Prospectus) give the team a 96.0% chance of winning the division; FanGraphs, while marginally more pessimistic at 94.5%, still believes the same. This comes as no surprise to Baltimore fans, who have witnessed the team’s post-All Star Break hegemony and contemporaneous mediocrity from Toronto and New York. No, what the Oriole faithful care about now is how well this club will do once it reaches the postseason. That performance will hinge on several players, one of whom dominated last night.
For the season as a whole, Chris Tillman has been lucky. His 3.55 ERA overshadows a 4.32 xFIP and 4.39 SIERA; the former number ranks 47th out of 94 qualified pitches, but the latter two come in at 80th and 81st, respectively. In yesterday’s game against the Chicago White Sox, however, he didn’t derive his success from luck, but from skill: Striking out nine South Siders while only walking one, he supported his 1.13 ERA with a 2.20 xFIP and a 2.07 SIERA in Baltimore’s 5-1 victory.
This was no fluke for Tillman. In his past five starts, he owns a 2.14 ERA, with a 2.79 xFIP and 2.78 SIERA to go along with it. Compare that to his previous 22 outings, in which he posted a 3.92 ERA, 4.71 xFIP, and 4.78 SIERA, and you see that he has made notable — and legitimate — improvements to his game. Should this trend continue, it would bear well for the Birds come October. Digging a little deeper, we see that there’s evidence to suggest it will.
Strikeouts and walks have actuated Tillman’s step forward; whereas earlier, he fanned 14.6% of opposing batters while issuing free passes at a 9.0% rate, now he has bettered those numbers to 25.0% and 2.4%, respectively. Pinning the former two rates at 14.3% and 9.1%, respectively, Mike Podhorzer’s xK% and xBB% formulas substantiate his initial struggles. Those equations don’t feel as confidently about his recent achievements, as they think his strikeout and walk rates should be 21.0% and 6.2%, respectively; nevertheless, those still significantly exceed his theretofore rates. Moreover, looking into those statistics shows the causes of his improvements: He has accrued more swinging strikes (14.5% S/Str%, as opposed to 10.1% before) and has thrown more strikes as a whole (65.8%, as opposed to 62.2% before).
Now, this is where the trends come in. As I said earlier, regular season output doesn’t make all that much of a difference to the Orioles right now. They only care (or, at least, they should only care) about what will happen after the season’s conclusion. So they, presumably, would like to know if Tillman has actually turned the corner, and if they should give the ball to him in Game 5 of a postseason series.
Obviously, Tillman’s aforementioned xFIP and SIERA marks give credence to his ERA, and his xK% and xBB% marks do the same for his xFIP and SIERA. But why has he seen an increase in efficacy as of late?
Tillman hasn’t gained any noticeable velocity or movement, nor has he momentously altered his pitch location. He has decreased his changeup usage a bit, but it doesn’t seem like enough to cause all this. Instead, I feel as though something else is behind this: his delivery. Look at these screenshots of him — first, from Opening Day’s win over the Boston Red Sox:
And, by contrast, from August 8th’s rout of the St. Louis Cardinals:
They seem fairly analogous, right? Look at Tillman’s feet. The delivery hasn’t changed, but its location has — he now throws further to the right of the rubber than he ever has. The data back this up too, as the following chart shows:
|Pitch||Average Horizontal Release Point (1-22)||Average Horizontal Release Point (23-27)|
Does a move to the right grant someone greater ability to deceive? If the first eight years of this millennium were any indication, it does. In all seriousness, though, this strikes me as the most plausible explanation for Tillman’s recent success, since there don’t appear to be any others. I’m far from an expert on the matter, but this also seems like something that Tillman can easily maintain; if he does — and if it continues to bring him the same results — he could be a weapon for the Orioles going forward.
All statistics courtesy of Baseball-Reference.