A look at Mike Shildt’s starting pitcher hook

Managerial firings in St. Louis are few and far between. When the Cardinals axed Joe Torre in June of 1995, José Oquendo was in the midst of his final season as a player while John Mabry would ultimately bat .307 en route to a fourth place finish in NL Rookie of the Year voting. Die Hard with a Vengeance was tearing up the box office, “Have You Ever Really Loved A Woman?” by Bryan Adams held off Montell Jordan’s “This Is How We Do It” atop the Billboard Hot 100, and a pair of leather gloves captivated the nation.

Needless to say, the title of Cardinals field manager has been anything but a revolving door, especially during the current Bill DeWitt era in franchise history. While the Marlins, for example, have switched managers 16 times since the beginning of the 1996 season, the transition from Mike Matheny to Mike Shildt marked just the second such change in St. Louis over that 22-year timeframe.

Even with their recent hiccups, the Cardinals have posted the best record in the National League under Shildt’s watch, catapulting from measly 7% playoff odds entering August into the thick of the pennant chase as the interim skipper received an extension through 2020 last month. As my colleague A.E. Schafer wrote, “it’s important to always remember that Shildt didn’t just show up this summer, or when he was promoted to the big league staff; the Cardinal organisation has been grooming him for a position like this for a dozen years at this point.” Some national writers were quick to question the decision to remove the interim tag after a mere 38 games, but the point remains that the Cardinals are quite familiar with Shildt and evidently committed to him as their manager going forward.

Digital ink has already been spilled at VEB regarding facets of Shildt’s managerial skillset ranging from his handling of veteran players to double-switching prowess, but today we are honing in on one of the fatal flaws of his predecessor: making the call to pull–or not to pull–the starting pitcher.

The secret is out that starting pitcher performance significantly declines upon facing the opposing lineup for a third time. Between higher pitch counts that arise from working deeper into a game, hitters receiving more opportunities to see the pitcher directly from the batter’s box, and a variety of other factors, generally speaking, the optimal decision for a manager is to proactively make the slow stroll to the mound before a starter gets burned a third time through the order.

As for Shildt’s starting pitcher hook savviness, let’s begin by looking at how often he has let his starter venture into the third time through the order gauntlet.

Compared to his 29 peers, Shildt appears to be relatively progressive when it comes to pulling his starters sooner rather than later. Prior to his firing, Matheny allowed his starters to head back out for a third time with the 12th highest frequency in baseball, down from fifth and eighth most often over 2016 and 2017, respectively.

So that’s it? Case closed? Not quite. Consider that not all third trips through the order are created equal. The risk in pushing the envelop with your starter in a 10-3 blowout is drastically less than the same decision in a nailbiter tied at three runs apiece. While the Shildt-led Cardinals may have an overall quick starting pitcher hook, a disproportionately high amount of their third time through the order plate appearances occur in what FanGraphs classifies as “high leverage situations,” the times when excessively working your starter is most perilous.

Despite having the ninth lowest total batters faced (TBF) count in the relatively harmless “low/medium leverage PAs” column, Shildt ranks 11th largest in “high leverage PAs” during his time at the helm.

To quantify how much each individual manager’s starting pitcher hook has helped or hurt his respective club, I am resorting to a method similar to the one I used in my Mike Matheny is too slow to replace starting pitchers article from around this time last season.

I needed a way to measure a manager’s trust in his starter as the game progressed. I looked at every plate appearance that occurred during a starter’s third time–and only his third time–through the order in addition to being classified as a “high leverage” situation. (Any game event with a leverage index above 2.0) If that seems like a hyperspecific filter, just keep in mind that there were numerous variables I needed to account for.

In many instances, the second time through the order is simply too early for a manager to go to his bullpen without expanded rosters.

Stats from the fourth time through the order become too unstable to use for two reasons: 1) The sample size drastically shrinks; 2) Starters lasting that deep into a game are likely the beneficiary of “survivor’s bias”. (Not only is this a more talented group to begin with–how often do you see a terrible pitcher toss a complete game?–, but they have also been pitching exceptionally well on that particular day.)

Managers are more willing to push the envelope with their starters in low leverage, blowout games. Is it worth burning a reliever for tomorrow to keep one or two runs off the scoreboard in the seventh inning of a 9-0 landslide? [...]

With the game on the line and the advantage shifting from the starting pitcher to the batter, righting the ship with your starter is rarely the sabermetrically sound decision. However, like seemingly everything in baseball, context is key. A manager with an excellent rotation and an awful bullpen should, in theory, have a “slower hook” than the average club.

What am I doing this year is calculating the difference between the starting pitcher FIP in the described high leverage, third time through the order situations and that team’s overall bullpen FIP in the time being tested. In Shildt’s defense, the Cardinals’ relief core has been...er, less than stellar as of late, so could he reasonably justify letting his starters tackle the pivotal moments of a game on accounts of the alternative being poor bullpen performance?

Ouch. If we assume that approximately 10 runs equates to one win and that high leverage situations are at least twice as significant as the average game event, one could deduce that the Cardinals, fighting for their lives in a packed National League playoff hunt, have cost themselves at least half a win since mid-July alone due to employing a mistakenly long leash at the worst possible time.

Granted, these numbers are possibly exacerbated by small sample size flukiness, but as the chart below displays, every* St. Louis pitcher to record a start in 2018 has notably worse career splits the third time through the order than the first two. It shouldn’t come as much of a surprise when a Cardinals hurler suddenly hits a wall the third time around.

*I note the lone exception as a single tear rolls down my cheek.

The jury that matters (i.e. Cardinals front office and ownership personnel) is decisively all-in on Mike Shildt as manager. To me, at least, he has thus far been neither an elite, upper-echelon tactician nor one who regularly embarrasses and frustrates fans like Matheny did. I am of the belief that the impact a manager has on his team’s success is generally blown out of proportion, but as I have stated in the past, I certainly wouldn’t mind the Cardinals experimenting with more revolutionary approaches to pitching substitutions in attempts of gaining a competitive advantage.