Brandon Morrow’s Left On Base Blues

Has it ever happened to you where one number — just one measly stat — throws your mind on a complete tangent, and results in you wasting a half hour of your life? This happens to me more often than I should admit. For instance, I was taking a stroll this morning through the FanGraphs leaderboards when one stat jumped out and lodged itself in my brain. Oh look, Brandon Morrow’s swinging strike rate (11.5%) was the second highest in the majors last season. That’s not even a surprising statistics; I know Morrow is a strikeout ace, and that his ability to get hitters to swing and miss is among the best in the game. But for some reason, the stat wouldn’t leave me alone.

Me: Didn’t Morrow just sign a new contract extension?

Other Me: Yes, that’s right — 3 years, $20 million.

Me: So the Blue Jays must think his ERA will eventually fall in line with his peripherals, right? You don’t make that sort of a commitment to a 4.50 ERA pitcher, and the Blue Jays are smarter than that. Morrow did post a 3.31 SIERA these past two seasons…

Other Me: They must. But Morrow’s problems have largely stemmed from an inability to strand runners on base (<70% LOB% over past two years).  Could this possibly be a pitch selection problem? Or maybe Morrow isn’t able to go to his best whiff pitch when runners are on base, for whatever reason?

Me: For that matter, what is Morrow’s best swing-and-miss pitch?

Other Me: Uhhh…

Just like that, one simple statistic turned into a full-blown investigation.

When I dug into Morrow’s pitch selection, one flashing red light jumped out at me right away: Morrow is essentially a two-trick pony. He throws his four-seam fastball around 60% of the time, and he uses his slider 30% of the time; for the remaining 10% of his pitches, he mixes in 87 MPH sinkers and see-me curveballs.

Morrow has a great four-seamer (94 MPH, 20% whiffs), but his real weapon is his slider. He throws his slider are 87 MPH, and he gets both righties and lefties to swing and miss at it 32-36% of the time. As you’d expect, he uses his slider as his out-pitch; if he gets ahead on a hitter, he starts pounding them with sliders again and again.

Why is this important? Generally speaking, it’s difficult for pitchers with only two pitches to succeed as major-league starters. It’s impossible for pitchers to keep hitters off balance if they have a limited stock of weapons, and most pitchers with a small repertoire get moved to the bullpen. As Mariano Rivera shows, you can blow hitters away with only one or two pitches when you’re coming in for short stints…but starting a game is a whole different story.

That is not to say that Brandon Morrow should get moved to the bullpen. Morrow already has two dominant pitches, so all he needs to be a successful major-league starter is to add in another pitch or two to keep hitters off balance, even if those pitches aren’t super strong. That’s probably why Morrow has been experimenting with a sinker and curveball over the past few years; if he wants to take his game to the next level, he needs to add in at least one other decent offering.

Right now, this hole in Morrow’s game becomes very apparent when men get on base. When nobody is on base, Morrow is able to work in his sinker and curveball 9% of the time — not a huge amount, but often enough to at least keep hitters honest. But when men reach base against Morrow, he quickly ditches his weaker pitches (presumably because he’s less confident in them) and becomes almost solely a fastball/slider guy. Not only that, but Morrow actually throws his four-seam fastball less often when men get on base, preferring to throw his slider anywhere from 32-38% of the time.

Obviously, something isn’t working with this approach (2011 data):

	K%	BB%	Avg	BABIP
Bases Empty	25.8%	8.7%	0.217	0.273
Men On	26.5%	9.2%	0.255	0.335
Men In Scoring	26.3%	10.2%	0.272	0.355

So Morrow’s strikeout rate ever-so-slightly increases with men on, but his walk rate ticks up by a much larger amount. He’s also much more “hittable” when men are on base, which likely has to do with some bad luck…but also may be related to the fact that when put in play, his slider is much more likely to fall for a hit than his fastball. And when you combine all that with the fact that Morrow becomes more predictable with men on base, well, is it really a surprise that he’s struggled in those situations?

As his 11.5% whiff rate shows, Morrow is one of the best starters in the majors based on pure stuff alone. But until he finds a consistent and effective #3 pitch that he can use with runners on base, I’m skeptical that he will improve that much going forward. With some better luck on balls in play, he could end up in the 4.00-4.30 ERA range, but I think he’ll be hard pressed to do better than that with only two pitches.

The encouraging news? Pitchers who are as good as Morrow shouldn’t have too difficult a time learning another pitch. It may take time for him to make the transition, but the Blue Jays should keep on hammering away. Morrow has too much potential for him to forever remain a two-pitch wonder.

Thanks to the Joe Lefkowitz Pitch F/x tool for most of the data and research in this post.