Fluke improvement watch: Jered Weaver

Jered Weaver is an odd pitcher. He’s a guy who has always been thought of as a potential ace. Despite this, while his ERA was solid in 2007 and 2009, before 2010 he hadn’t managed to replicate his amazing strikeout-to-walk numbers in the minors. However, this year that changed, with Weaver’s K/9 rising for the first time above 8 to 9.35 and his BB/9 falling to a career-low 2.17. Even Weaver’s groundball rate improved this year to 36 percent, a good rate for a guy who is basically an extreme flyball pitcher. What changed this year? Is Weaver likely to repeat it? Well to answer that, let’s look at his pitches:

Weaver throws five different pitches: a four-seam fastball with strong cutting action, a two-seam fastball, a change-up, a slider, and a “curveball.” I say “curveball” because the pitch really doesn’t have a typical curveball movement, but rather seems to have the same movement as Weaver’s slider, but is around 7-8 mph slower than the slider. The two-seam fastball, it should be noted, is the newest pitch; it only really began to be used significantly in 2009. The various pitches and their movements and velocities this year are listed below:

Pitch Type Average Velocity Average Horizontal Movement Average Vertical Movement
Change-Up 78.43 Mph -6.10 +10.03
Four-Seam Fastball 90.13Mph -0.85 +11.65
Two-Seam Fastball 89.45Mph -6.11 +10.63
Slider 78.95Mph +3.45 -0.36
Curveball 70.50Mph +4.54 -1.95

Of these pitches, the four-seam fastball has some nice cutting action, but really that’s the only impressive thing about the movement or velocity of any of these five pitches. And that basically has stayed the same all of the last three years. The only difference in his pitch movement this year from last year is that the four-seam fastball and two-seam fastball seem to have become slightly more distinct, with the difference in the horizontal movement of each pitch growing by around an inch or two. Clearly, what success Weaver has had in the past, and this year, has not come as a result of extraordinary movement on his pitches. It has come from an understanding about how each of his pitches work, when to use them, and some pretty good control.

Okay, so the pitches’ movements haven’t changed in any way that would cause Weaver’s improvement. So how about Weaver’s pitch usage? Well, Weaver has increased his usage of the two-seam fastball and the curveball against left-handed batters. (On 0-0 counts to such batters, the curveball oddly enough is the most used pitch.) Against right-handed batters, there doesn’t seem to be much change in his pitch usage.

Moreover, Weaver’s been able to seemingly increase his ability to concentrate certain pitches, including the aforementioned curveball in locations just at the edge of the strike zone, or at barely outside of the strike zone. The end result is that batters are swinging more at pitches of Weaver’s that are located outside of the strike zone. The end result is that Weaver has been better able to get into two-strike counts than he did last year, resulting in more opportunities for strikeouts.

And when he gets to two-strike counts, Weaver’s style is such that really aims to get the strikeout. He basically avoids the strike zone entirely on 0-2 (and less so, but still similarly so on 1-2), resulting in pitches that generally can at worst result in a ball, and at best result in a strikeout or weak contact. There really isn’t much change here, but it should be noted as to how Weaver pitches in these counts if we’re talking about understanding Weaver’s pitches.


Jered Weaver emerged as a bona-fide ace this last year. His peripherals show that the results weren’t just the result of BABIP luck. His pitches themselves would seem to indicate to me that this is likely not just a random fluke for other reasons (batter failures) either. Weaver should be able to maintain a similar performance next year. As such, I would perhaps even go so far as to say that he would be a worthy first starter on your fantasy team next year (even more so if it’s an AL-only league).

Print This Post
Sort by:   newest | oldest | most voted

@AA, There’s nothing I can see to show that he’s deliberately changing speeds or that a 3rd fastball is there.  His velocity changes are likely due to the natural variance of human action, not due to varying speeds deliberately.


Also of note is that Weaver is a pitcher who varies the speed of his 4 seam fastball significantly.  He commonly throws 94, then drops to 89-90.  It makes me wonder if 1) he throws a third fastball or 2) is actively varying his velocity.

Brad Johnson
Brad Johnson

It used to be more common for pitchers to throw a BP fastball which is just the same grip ratcheted back in the hand. Some guys get a little extra movement on the pitch. That could be what you’re observing Weaver do.