Justin Verlander and the case of the hanging changeup

In retrospect, perhaps it should have been easy to foresee Justin Verlander's decline coming into the 2014 season. The man laughed in the face of pitch counts for years, had lost some velocity the previous season in 2013, and had just turned 31.

At the time I mused about the wear and tear on Verlander's arm, but really I was having a casual muse more than making a point or a prediction.

Since 2009 Justin Verlander has thrown 1517 more pitches than anyone else in baseball for a total of 19,084. #wearandtear

— Nick Ashbourne (@Nick_Ashbourne) January 18, 2014

The Tigers ace always had an air of invulnerability around him, and it just didn't seem possible that he could fall to earth so quickly.

To be fair to Verlander, word of his demise has been greatly exaggerated. Although his 4.54 ERA last season was somewhat shocking, his 3.74 FIP was much better. Verlander's 3.3 WAR ranked 29th among Major League pitchers, meaning his performance resembled that of a "number one starter", albeit a pretty bad one.

Velocity loss is usually the first explanation given to explain the 2011 MVP's troubling season, and it surely played a role. It doesn't take a rocket scientist to interpret these velocity charts from FanGraphs.

The days of Verlander touching 100 in the ninth inning—or ever, for that matter—are long gone. The 31-year-old is still a power pitcher, but he's not a fireballer any longer. This has lessened his margin for error significantly, which helps explain why he was hit much harder last season.

While this explanation is a logical one, it is not the only factor at play. Verlander's fastball wasn't the only pitch that was less effective for him last year; his changeup was also significantly worse.

The lazy way to explain this phenomenon would be to say that his declining fastball velocity led to a smaller difference between his heater and his changeup, rendering the latter a less effective offering. That is a possibility, but pitchers like Felix Hernandez and Henderson Alvarez have shown that there is far more to changeups than a big velocity difference from a pitcher's fastball.

In Verlander's case the other factor at play is location. Generally speaking, changeups are designed to be thrown low in the zone or below. The ideal change starts in the zone looking like a low fastball and drops out of it at the last minute leaving the batter chasing a pitch too low to do any damage on.

There are more than one ways to skin a cat of course, but changeups are usually most effective low. Just like any off-speed pitch, when left high they can be turned on and crushed. Verlander saw this happen to him a few times last season:

Bad things tend to happen when you leave changeups high, and last year Verlander did so more than ever before. For the purposes of the chart below I've defined "high" as in the middle third of the strike zone and above.

Year	Changeups Thrown	‘High’ Changeups Thrown	High Changeup%	FanGraphs Pitch Value
2008	679	325	47.9%	2.7
2009	402	165	41.0%	7.3
2010	587	232	39.5%	11.3
2011	724	272	37.6%	10.3
2012	803	298	37.1%	4.9
2013	657	271	41.2%	2.0
2014	971	506	52.1%	-3.5

Verlander left more than half of his changeups higher than they probably should have been last year. His 506 "high" changeups last year were 149 more than the league's second highest total (357 by John Danks). Even allowing for some classification errors on slower fastballs, that is extraordinary — and not in a good way.

Unsurprisingly, hitters turned these pitches into extra-base hits.

What this information tells us is that not all of what went wrong with Verlander in 2014 was age-related decline. His hanging changeup issue was a product of execution, perhaps due to something mechanical although it's hard to say.

It's more or less written in stone that Justin Verlander's best days are behind him, but there are some things he can do to bounce back from his performance last year. Commanding his changeup better is at the top of that list.

. . .

All statistics courtesy of FanGraphs, Baseball Savant, and Brooks Baseball

Nick Ashbourne is an Editor for Beyond the Box Score. You can follow him on Twitter at @Nick_Ashbourne.