The science behind Rockies pitcher Ubaldo Jimenez's nasty stuff
Numbers and stats are absolutely central to baseball, adding immeasurably to the fun of the game. That's why DriveLine Mechanics' ultra-wonky breakdown of Colorado Rockies pitcher Ubaldo Jimenez's approach is fascinating rather than bizarre.
Jimenez, the probable starter tonight against the Los Angeles Angels of Anaheim -- who fell to the Rocks last night, giving Colorado's ballers seventeen victories in the last eighteen games -- is only 6-6 this season. Like the team as a whole, however, he's been on an upward path of late, and blogger vivaelpujols thinks he knows why: Jiminez usually relies early on his devastating fastball, but begins mixing in other pitches to a greater degree as the game goes on, allowing him to maintain fastball velocity while adding to hitters' uncertainty. And Driveline Mechanics offers a slew of graphs to prove it. Check them out:
This scatter chart shows the distribution of Jimenez's pitches, graphed by their relationship to vertical and horizontal movement.
This graph tracks Jimenez's pitch selection through seven innings.
As seen here, Jimenez's number of off-speed pitches goes up later in games.
Likewise, his fastball percentage dips in later innings.
The piece concludes: "It's likely that throwing less fastballs and more offspeed pitches improves the effectiveness of both of them. When you are mixing a 95 MPH fastball with slow stuff, the fastball looks a lot faster and hitters will have less time to react to it. Similarly they will be out in front of the slower pitches. Conversely, hitters can hit a fastball, no matter how hard it is, if they know it is coming. This certainly seems like something worth looking at more in depth, in relation to Jimenez and the league as a whole."
That probably means more charts like the ones above -- and I'm all for that.