Jake McGee has become one of the most dominating relief pitchers in the past year, taking the closer role from Grant Balfour, and becoming part of a bullpen team known as "Jake and the Box." While most starting and relief pitchers rely on a combination of different pitches, McGee relies heavily on his high-velocity 4-seam fastball to strike out the batter, which he uses an astounding 96.49% of the time (per baseball prospectus). The other 3.5% is a slurvy curve.
As the batter steps up to the plate, they know exactly what pitch McGee is going to throw, and they still strike out 33% of the time. His career ERA is a measly 1.89 in 2014.
How does he do this? How can a pitcher be so effective with only one pitch?
Jeff Long of Baseball Prospectus recently wrote an article about McGee to explain:
So how is McGee successful? First and foremost, he throws 100 mph. There is also the movement, which despite being fairly unremarkable in its variability is impressive in its magnitude. But probably the most important component is that McGee has elite level command of his 95-plus mph fastball.
In his article, Long shows that McGee uses that command to throw his fastball either down the middle or to the outside 82% to left handed hitters, while Right handed hitters see more diversity, although most pitches are still up and on the outside part of the zone.
The Rays seem to think that the best way to use Jake McGee's elite left-handed fastball to beat a lefty batter is to pound the outside of the plate for strikes. That strategy brought up a couple of questions. First does it just apply to Jake McGee, or is it something of an organizational philosophy? Second, How does McGee compare to other one-pitch fastball-heavy relievers in the game?
David Price vs Jake McGee
The most famous lefty that the Rays have produced is David Price. I took data from Brooks Baseball and specifically looked at Price's and McGee's approach to Left Handed Hitters in 2014 using just their fastballs:
The charts above show that their strategy is almost identical against LHH, with McGee being slightly heavier on outside of the zone.
This seems to support our theory of Rays pitchers attacking same handed hitters the same way. But what about other top relievers?
Sean Doolittle vs Jake McGee
The only lefty reliever to throw their fastball as much as Jake McGee (1101 times per BP) is Sean Doolittle (790 times). Using the same criteria as above, lets take a look at how they compare when attacking LHH:
Completely different approach. Doolittle likes to attack way up into the zone, and that results in a 37% K rate and a 2.73 ERA in 2014, although that is high compared to his 1.71 FIP (per FG).
Looking at McGee's chart compared to Doolittle and Price, you can see that elite command that Long was talking about. The fastball pitches are in very specific and determined locations of the strike zone. Doolittle's fastballs, while undeniably effective, are more spread out within the zone.
Jake McGee is obviously a master of his craft. Even while using only one pitch, he still can dominate all types of hitters. Part of that is because it's an elite pitch, with top-level velocity and movement, but Mcgee isn't simply rearing back, closing his eyes, trusting his stuff.
David Price could throw other pitches, yet the Rays chose to have him pitch against lefties the same way that Jake McGee does. They appear to think that when a fastball is that good and when a pitcher is able to locate it on the outside, then other pitches simply aren't worth the opportunity costs.
Maybe it's time we stop worrying about the fact that McGee can't throw anything else. Against lefties at least, anything else would be a step down.