Despite missing the first month-and-a-half of the season, Los Angeles Dodgers closer Kenley Jansen has put together a strong 2015 campaign. His 1.77 xFIP and 11.75 K/BB rank second among relievers with at least 20 innings, and he has 19 saves out of 20 chances.
But there are some disconcerting signs, as well. In just 26.2 innings, Jansen has already allowed five home runs — the same number that he totaled in 65/1 innings last year. Four of these home runs came in July, when he saw his ERA balloon from 1.08 to 2.81.
Why has Jansen struggled lately? This ESPN report provides one crucial indication:
The concern is more the direction than it is the result of that,” [Don] Mattingly said Saturday, referring to Jansen’s mechanics. “If his direction’s right, then the ball’s going to come out differently and they’re not hitting home runs. The concern is making sure that he stays in line as far as mechanically where the ball comes out.”
Jansen’s struggles stem from pitching mechanics that relate to “where the ball comes out.” In other words, his release point. The following graphs from Brooks Baseball confirm these issues.
First, here’s the horizontal release point for Jansen’s cutter, which he throws approximately 85 percent of the time:
We see a noticeable difference between this year and the past two years. Whereas Jansen released his cutter about 2.3 feet to the right of the rubber in 2013 and 2014, he’s been closer to 2.7 feet lately.
The same trend exists for the vertical release point:
In 2013 and 2014, Jansen threw the cutter from around 6.4 feet. This year, his release point has dropped below 6.3 feet.
These changes matter because they affect how Jansen’s pitches moves through the strike zone. While his vertical movement has largely remained the same, horizontal movement has declined:
In 2013 and 2014, Jansen’s cutter moved over three inches horizontally on average. This year, it’s lost about an inch of movement.
That may not sound like a lot, but it makes a significant difference when you’re trying to paint the corners of the plate. We can see these effects quite vividly through the following Baseball Savant heat maps, which show the location of Jansen’s cutters over the past three years:
Note that, in the first two maps, Jansen’s cutters are fairly compact around the strike zone, reflecting good command in 2013 and 2014. In the last map (2015), it’s more scattered and fragmented — not what you’d want from your closer.
Moreover, 2015 has a prominent red spot near the center of the strike zone. It tells us that Jansen is hovering around the middle of the plate, with over 10 percent of his cutters going to this area — the most frequent location for the pitch. That’s an increase from his 7.5 career percent mark.
Obviously, the middle of the plate is not where a pitcher wants to be. When Jansen’s cutter finds itself there, opponents have a .232 batting average and .348 slugging percentage lifetime. By contrast, when he’s at the corners, they bat around .180 and slug around .260.
Based on media accounts, as well as Jansen’s overall performance this year, his mechanical issues don’t seem to be a lost cause. In fact, it’s a good sign that Jansen’s needs are clear and coaches are already addressing them. Nevertheless, as the Dodgers continue their postseason hunt, the cutter is something that deserves our ongoing attention.