Just before the trade deadline last season, the St. Louis Cardinals acquired former closer Jonathan Broxton from the Milwaukee Brewers in exchange for then-20-year-old prospect Malik Collymore. Broxton was solid out of the bullpen for the Cardinals after the trade, posting a 2.66 ERA over 26 appearances (23.2 innings pitched). However, Broxton’s FIP registered nearly a full run higher at 3.56 (ballooned by an awful walk rate of 11.9%), and this ERA-FIP difference subsequently cast reasonable doubt as to whether or not this performance was sustainable over a larger sample.
Yet, considering there were holes to fill in the 2016 bullpen (Matt Bowman was added via the Rule V draft one day after Broxton signed, and Seung Hwan Oh did not sign until January), general manager John Mozeliak seemingly tossed said doubt aside by inking Broxton to a two-year, $7.5 million deal on December 10th, 2015, just over one month after buying out his club option for $2 million (most likely using the money received from the Brewers in the trade).
In a vacuum, meaning ignoring both peripheral statistics and readily-available PitchF/x data, the signing was questionable, at best, from the very beginning. Relief pitchers are inherently volatile (stressing the importance of one-year deals), and this volatility can be taken a step further when you are introduced to the fact that said reliever will turn 32 years of age only two months into his first season of the contract.
Fortunately, multi-million dollar signings do not occur in vacuums. The general manager of the Cardinals, along with GMs throughout the league, had access to Broxton’s peripheral statistics and PitchF/x data just like all of us currently reading this post. In addition, through Statcast and TrackMan, Mozeliak (and staff) almost certainly knew even more than the general public about the free agent reliever, from spin rate to perceived velocity to horizontal movement. Yet, despite the various warning signs — including, but not limited to, a very high walk rate and decreased fastball velocity — Mozeliak re-signed Broxton to, and I must reiterate this point, a two-year contract.
The 2016 season
Using Broxton’s 2015 FIP (3.65) and/or Dan Szymborski’s ZiPS as a rough guide, one could have projected the right-handed reliever to post an ERA in the mid-3’s and provide a shade over league-average value (0.3 zWAR) out of the Cardinals’ bullpen in 2016. However, through 47 appearances (41.2 innings), Broxton has actually performed below replacement level at -0.1 fWAR and -0.3 rWAR.
For those not interested in sabermetrics, Broxton’s 2016 ERA is currently 4.75 — tied for 9th highest (with Fernando Salas) among MLB relievers with a minimum of 40 innings pitched. While Broxton still has time to improve on his 2016 season, none of his current statistics point toward a better performance down the stretch — as he has experienced a low in-the-zone rate (47.9%), O-swing rate (31.8%), and BABIP against (.252).
2016 appearances by leverage index (LI)
Before discussing how leverage index applies to failure that is Broxton specifically, let me first explain what leverage index (LI) actually is — a useful statistic provided by the smart people over at FanGraphs. It is a statistic that allows us to get a grasp on what types of situations relief pitchers appear in over the course of the season, and ultimately, over the course of their respective careers. A leverage index of 0-0.85 is considered “low” leverage, 0.85-2 is “medium” leverage, and anything greater than 2 is “high” leverage.
There are various subsets of LI (gmLI, inLI, exLi), but gmLI, specifically, provides the average leverage index at the very moment a pitcher enters the ballgame. Hence, the value behind gmLI is getting a sense of whether or not a reliever’s manager trusts the pitcher to be used in high leverage situations.
Well, overall, manager Mike Matheny has deployed three relievers with a higher gmLI than Broxton (0.94): Kevin Siegrist (1.75), Trevor Rosenthal (1.48), and Seung Hwan Oh (1.37). Considering all three relievers are better than Broxton (debatable with the possibly-injured Rosenthal so far in 2016), this a good thing. That being said, the graph provided below is a rather alarming development, especially considering the fact that Broxton has hovered right around replacement level virtually all season.
I will be the first to admit that I am no statistician (unlike a handful of VEB readers). However, I can do a decent job at spotting trend, and there is a definite upward trend seen in the graph above. The x-axis represents each one of Broxton’s games this season, from appearance number one on April 5th to appearance number 47 two days ago on August 6th. The y-axis represents the average leverage index (LI) when Broxton entered the game (also known as gmLI).
Well, as you can see around the 32-year-old righty’s 24th appearance of the season, Matheny has begun to consistently use Broxton in higher leverage situations. In fact from appearances number 24 to 47, Broxton’s average gmLI has been 1.31 — a significant increase from an average gmLI of 0.54 over his first 23 appearances of the season. Despite no real improvement in performance, Matheny has entrusted Broxton to some of the games’ most critical situations — which makes no sense considering the availability of Tyler Lyons, Matt Bowman, and even a possibly-resurgent Seth Maness beyond the two usual stalwarts in Oh and Siegrist.
While I was openly critical of the trade at the time, Mozeliak and the Cardinals will probably end up on the positive side of last year’s trade deadline deal with the Brewers. Collymore, now 21, is no longer an infield prospect (severely hampering his future value) and has struggled mightily in his first season above rookie ball, slashing .180/.255/.227 over 141 plate appearances with the High-A Brevard County Manatees — an underwhelming slash line even for the offensively-challenged Florida State League.
The same cannot be said about the next two transactions directly involving Broxton. On the surface, buying Broxton out of his 2016 club option for $2 million was absolutely the correct thing to do (especially if the Brewers did indeed send $2 million along as well), but considering the next move, made just over a month later, clouds surround the buy-out decision as the team then agreed to a two-year deal worth $7.5 million. Remember, deals with relievers, volatile by nature, are best left at one year, maximum. Unless, of course, you are dealing with an elite reliever (i.e. Andrew Miller) — of which only a handful truly exist.
Thus, from the beginning, the Broxton deal was destined to fail, and the blame here falls solely on the Cardinals’ typically-steady general manager. However, this failure has since become an organizational one as the team’s field manager continues to use a middling reliever in higher-leverage situations. Over the course of 162 regular-season games, especially involving a team as inconsistent as the 2016 Cardinals, there are plenty of low-leverage opportunities for underperforming relievers. Instead of upping Broxton’s workload with medium- to high-leverage situations, Matheny should return to using him in lower-leverage roles, just as he did earlier in 2016. Or, Mozeliak can make things even easier for everyone by accepting failure and cutting Broxton outright.