Kenley Jansen Is Fighting the Clock, but He’s Hardly Alone

Kenley Jansen
Nathan Ray Seebeck-USA TODAY Sports

As an East Coast dweller with a habit of watching West Coast broadcasts (and particularly Dodgers games) after the work is done and the kiddo tucked in, I’m well aware of Kenley Jansen’s evolution toward what we might politely call a more deliberate approach to pitching. Indeed, over the course of his 13-year major league career, he has evolved into one of the majors’ slowest workers on the mound. With this year’s introduction of a pitch clock, he spent the offseason working to adjust his delivery and is facing as much pressure as any pitcher to adapt to the new rules, though he’s hardly alone.

On Thursday, The Athletic’s Andy McCullough and Jen McCaffrey had some choice quotes from Jansen, who joined the Red Sox this year via a two-year, $32 million deal, on the subject of his tempo. Last year, while a member of the Braves, he saw his name atop an MLB Network graphic of the slowest-working pitchers. “I was so embarrassed,” he told The Athletic. “Like, dude, you’ve got to clean it up.”

“It drives me crazy,” he added. “Because I’m like, when did I get this slow?”

The topic is particularly relevant because Major League Baseball is adding a pitch clock this year, one that gives pitchers 15 seconds to begin their deliveries with the bases empty and 20 to do so with men on. MLB is also planning strict enforcement of the balk rule, because the aforementioned times require clarity on when a pitcher’s delivery starts, thus presenting an additional problem for Jansen.

The 35-year-old righty believes that the addition of a double swivel of his left (front) hip to start his delivery may have slowed his delivery down even as its addition catalyzed his resurgence. Stung by his reduced role in the 2020 postseason as the Dodgers finally won that elusive championship and hoping to regain velocity and command, he added the move in April ’21. By repeating a hip swivel that he’d previously introduced at the start of his delivery, he improved his balance, avoided drifting toward third base, and lengthened his delivery toward home plate. His results certainly improved: his average cutter velocity increased from 90.9 mph to 92.5, and his ERA fell from 3.33 to 2.22 (though his FIP and xERA barely budged). Last year, Jansen’s cutter averaged 92.2 mph, still faster than his 2018–20 velocities.

As you can see from the video above, the hip swivel is pretty subtle when viewed from the center field angle via which we typically watch pitchers, but the batter and umpire have a better view. That little movement matters because under the new rule, the clock stops at the start of the delivery, but what Jansen’s doing is a false start that can disrupt a hitter’s timing. Now in addition to speeding up his internal clock, he has to work on simplifying his delivery so as not to commit a balk.

While his hip swivel helps at least somewhat in explaining Jansen’s rebound in performance — mixing in his sinker and slider have helped as well — the data tell us he’s been throwing the brakes on his pace of work more or less since he assumed closer duties for the Dodgers in 2012, just three years after switching from catching to pitching and two years after reaching the majors. Last year, Statcast began publishing Pitch Tempo data, which measures the median time between pitch releases; not every pitch is accounted for, only those that were called strikes or balls. The Statcast measure differs from our lost-and-found Pace metric, which divides the time difference between the PITCHf/x timestamps of the first and last pitches of a plate appearance by the number of pitches in the PA minus one. Statcast also splits the data into into times with the bases empty and with men on base. Here’s what the data looks like for Jansen; by happy coincidence, the start of Statcast’s data coverage is the same year as his major league debut.

Jansen’s delivery times have generally been on the rise since he began pitching, with 2012, ’16, and last year standing out as points where he went from slow to slower to slowest. Pitchers as a group have been taking even longer between pitches over the same timespan, with the average with nobody on base increasing from 15.8 seconds in 2010 to 18.1 seconds in ’22, and from 22.2 seconds with nobody on in ’10 to 23.3 in ’22. Taking a page from contributor Chris Gilligan’s big-picture look at the attempts to improve the pace of play, here’s how the leaguewide tempo data looks alongside pace and time of game over the span of Jansen’s career:

Pace of Play Metrics
Season Avg Empty Avg Men On Pace Time of Game
2010 15.8 22.2 21.0 2:50
2011 15.8 22.2 20.9 2:51
2012 16.3 22.7 21.4 2:55
2013 16.7 23.1 21.9 2:58
2014 17.2 23.5 22.2 3:02
2015 17.6 24.2 23.2 2:56
2016 17.8 24.4 23.3 3:00
2017 17.3 23.5 22.7 3:05
2018 17.2 23.3 22.5 3:00
2019 17.7 23.9 22.9 3:05
2020 18.0 23.9 23.2 3:07
2021 18.3 24.3 23.7 3:10
2022 18.1 23.3 23.1 3:03

Note that last year reversed a years-long trend; the average time between pitches decreased relative to 2021, as did the length of the average nine-inning game. Those improvements have largely been attributed to the PitchCom signaling system, though two-year declines in strikeout and walk rates have helped as well.

While I could give you a pair of graphs comparing Jansen’s splits to the league averages, I chose attempt to index his splits (pitcher tempo divided by league tempo times 100) into what I’ll call Tempo+, which I think similarly gets the point across:

From 2012 to ’21, Jansen was around 30% above average with the bases empty and about 17% above average with men on, but last year he set highs in both categories, climbing to 42% above average with the bases empty and 35% above average with men on. Good thing he moved out of the Pacific time zone, or I’d have been even more sleep-deprived.

Anyway, among pitchers with at least qualifying 100 pitches with the bases empty in 2022, Jansen actually had only the third-longest time between pitches:

Pitch Tempo Trailers, Bases Empty
Pitcher Team Pitches Empty Tempo Empty
Jonathan Loáisiga NYY 179 25.8
Giovanny Gallegos STL 248 25.8
Kenley Jansen ATL 296 25.6
Kyle Finnegan WAS 297 25.5
Dominic Leone SFG 186 24.8
Devin Williams MIL 296 24.7
Andrew Bellatti PHI 217 24.6
Aroldis Chapman NYY 197 24.6
Alex Vesia LAD 241 24.5
Hunter Strickland CN 263 24.3
SOURCE: Baseball Savant
Minimum 100 qualifying pitches.

Jansen did edge Loáisiga for the highest percentage of slow pitches, with 22.3% of his offerings with the bases empty taking at least 30 seconds, compared to 21.2% for Loáisiga. Meanwhile, with men on base, Jansen took over the major league lead in average time…

Pitch Tempo Trailers, Men on Base
Pitcher Team Pitches On Base Tempo On Base
Kenley Jansen ATL 148 31.4
Giovanny Gallegos STL 153 30.8
Devin Williams MIL 183 30.5
Alex Colomé COL 143 30.3
Mark Melancon ARI 180 28.6
Hirokazu Sawamura BOS 193 28.4
Aroldis Chapman NYY 129 28.3
Kyle Finnegan WAS 178 28.2
Tony Santillan CIN 123 28.2
A.J. Minter ATL 186 28.0
Frankie Montas OAK/NYY 337 28.0
SOURCE: Baseball Savant
Minimum 100 qualifying pitches.

… but took a backseat to Gallegos in percentage of slow pitches, 58.2% to 57.4%; Williams (54.6%) and Colomé (51.7%) were the only other pitchers who topped 50% under those conditions. Gallegos might be the heavyweight champion of dawdlers, as his 33.8 seconds with men on in 2021 is the highest mark of the past seven seasons, and his 26.5 seconds with the bases empty that same year ranks third behind only Rafael Dolis (27.2 seconds in 2020) and Chapman (26.9 seconds in 2021). Jansen’s former teammate, the infamously slow Pedro Báez, has the second-longest split with men on, 32.9 seconds in 2015, and shaved just one second off that the following year.

It’s important to point out that Pitch Tempo doesn’t directly line up with the new pitch timer, which starts when the pitcher receives the return throw from the catcher and ends once he begins his delivery. Statcast publishes a Timer Equivalent that just subtracts six seconds from the tempo measure. Jansen’s Timer Equivalent measures of 19.6 seconds with the bases empty and 25.6 seconds with men on base would both constitute what former teammate Clayton Kershaw cheekily called “a shot clock violation” given the new regulations.

In terms of cleaning it up, Jansen is hardly alone. Using 100-pitch cutoffs for each split, last year 81 out of 523 qualifiers (15.4%) had timer equivalent averages over 15 seconds with the bases empty, and 56 out of 467 (12.3%) had averages over 20 seconds with men on. In both categories, the vast majority of the pitchers above those thresholds were relievers. In fact, only five pitchers who made at least half a dozen starts last year had timer equivalents greater than 15 seconds with the bases empty: Shohei Ohtani (15.7), Tylor Megill (15.3), JP Sears, Corbin Burnes, and Michael Kopech (15.1 apiece). Meanwhile, 16 starters had timer equivalents of at least 20 seconds with men on base, led by Montas, the only pitcher who cracked the tables above:

Pitch Timer Equivalent Trailers, Men on Base
Pitcher Team Pitches On Timer Eq On
Frankie Montas OAK/NYY 337 22.0
Josiah Gray WSN 415 21.3
Shohei Ohtani LAA 401 20.9
JP Sears NYY/OAK 198 20.9
Zac Gallen ARI 339 20.8
Cory Abbott WSN 124 20.8
Mike Clevinger SDP 272 20.7
Aaron Nola PHI 389 20.6
Blake Snell SDP 350 20.6
Brayan Bello BOS 244 20.4
Paul Blackburn OAK 278 20.2
Vince Velasquez CHW 219 20.2
Jeffrey Springs TBR 325 20.2
Andre Pallante STL 332 20.2
Beau Brieske DET 173 20.2
Max Fried ATL 419 20.2
SOURCE: Baseball Savant
Minimum 100 qualifying pitches.

In an odd coincidence, not only is Montas here but also Sears, one of the pitchers he was traded for last August, and just missing the cut with an average right at 20 seconds is another, Ken Waldichuk. To be fair, Montas was bothered by shoulder problems that sent him to the injured list late last year and resulted in surgery earlier this week; his 28.0-second tempo average with men on base was 1.5 seconds higher than in ’21, suggesting he might have been trying to give himself a little extra time to recharge between pitches.

Indeed, that’s the general theory for the increased time between pitches, particularly for relievers; they’re throwing short stints at maximum effort and so need a bit of extra time to get that velocity to where it can have the greatest effect. FiveThrityEight’s Rob Arthur previously found that every second of delay adds .02 mph to average fastball velocity, which is to say that waiting 10 seconds can add 0.2 mph. Earlier this week at Baseball Prospectus, Darius Austin took a deeper look at the tempo-velocity link in light of the rule change, particularly searching for pitchers able to avoid losing velocity while improving their tempo from beyond the new clock limits to more acceptable times:

[P]itchers in the slower tempo group were 32 percent more likely to have increased their velocity with runners on. It’s the bases empty comparison that shows the notable difference here, though: only 24.3% (17 of 70) pitcher seasons saw an increase in average fastball velocity accompanying a reduction in time between pitches. By contrast, 41.4% of the pitchers who took more time on the mound added something to their fastball, making it over 70% more likely that fastball velocity increased relative to those who sped up between deliveries.

Particularly as he’s now 35 years old, Jansen is at least well aware of the continuous work it takes to adjust, but maintaining his effectiveness while adhering to the new rules is as big a challenge as he’s faced on the field. Here’s hoping he can get time on his side.

Brooklyn-based Jay Jaffe is a senior writer for FanGraphs, the author of The Cooperstown Casebook (Thomas Dunne Books, 2017) and the creator of the JAWS (Jaffe WAR Score) metric for Hall of Fame analysis. He founded the Futility Infielder website (2001), was a columnist for Baseball Prospectus (2005-2012) and a contributing writer for Sports Illustrated (2012-2018). He has been a recurring guest on MLB Network and a member of the BBWAA since 2011, and a Hall of Fame voter since 2021. Follow him on Twitter @jay_jaffe... and BlueSky

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1 year ago

I’m not a doctor, but I’d also wonder if the pitch clock could be literally dangerous to Jansen? We know that closers have crazy heart rates even before they start pitching, and having to hump it up within a clock could exacerbate that. Jansen’s history of heart issues combined with this new clock is quite frankly a little scary.

1 year ago
Reply to  TKDC

If he medically cannot throw a pitch every 20 seconds then he shouldn’t be on the field to begin with.

1 year ago
Reply to  TKDC

The pitch clock wouldn’t be a danger to him.

Kenley Jansen has atrial fibrilation, or afib, that sometimes recurs. It’s a common irregular heartbeat. In 2018, he had a heart ablation procedure to reduce the possibility of it happening again. His heart went into afib in June 2022, and to get him back into normal rhythm, they performed a cardioversion on him, where they shock his heart back into normal rhythm.

In 2022, Jansen was placed on the IL on June 27, but Jansen himself dated the recurrence back to June 18, was checked out at the ER, then pitched the next day. He made 4 more appearances after that before deciding to have the cardioversion procedure, which he knew would put him on the IL for 15 days. So he made it through the series against the Giants and the Dodgers before going on the IL. After the cardioversion, he was fine the rest of the season.

There are two things (I know of) that triggered Jansen’s afib in the past: Denver and dehydration. The Red Sox play the Rockies at home this year, so at least he won’t have to worry about one of them.

Jansen is very aware of his heart condition, so I’m not worried about the pitch clock affecting his health. Whether the pitch clock will affect his performance, however… well, I hope the best for him.