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2019 report cards for starting pitcher hooks

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How baseball’s managers stacked up when it came to going to their bullpen at the right time

MLB: San Francisco Giants at St. Louis Cardinals Jeff Curry-USA TODAY Sports

A couple years ago, I brought out VEB’s good ole Mathenaging story tag and wrote about Matheny’s proclivity to allow his starting pitcher to remain in the game more so than his managerial peers. I found that his starting pitch hook in particular actually cost the Cardinals over a win’s worth of runs that season. Indeed: it was the best worst of times, it was the worst of times.

Having now completed the first full season of the Mike Shildt era, I decided to repeat my earlier exercise to see if the Cardinals were faring any differently under the latter. I’d recommend you read the original piece if you’re curious as to the methodology, but the long and the short of it is that I looked at how a team’s starting pitchers performed when being left in the game during a high leverage plate appearance the third time through the order versus how well that same team’s bullpen performed in 2019.

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?

First, I compared the starting pitcher weighted-on base average (wOBA) allowed in such situations versus the wOBA each club’s bullpen yielded. A negative value indicates that a team’s proverbial hook resulted in them leaving in a starter when their bullpen likely would have performed better.

SP wOBA vs. RP wOBA by team

Team SP wOBA RP wOBA wOBA points "saved"
Team SP wOBA RP wOBA wOBA points "saved"
WSN 0.197 0.337 0.140
MIA 0.171 0.331 0.160
BOS 0.230 0.314 0.084
CHC 0.255 0.312 0.057
LAD 0.255 0.287 0.032
COL 0.301 0.340 0.039
NYM 0.311 0.333 0.022
ARI 0.275 0.315 0.040
SDP 0.289 0.312 0.023
TEX 0.317 0.335 0.018
LAA 0.247 0.323 0.076
SEA 0.298 0.315 0.017
STL 0.279 0.289 0.010
HOU 0.300 0.296 -0.004
MIL 0.318 0.308 -0.010
CIN 0.315 0.307 -0.008
MLB Avg. 0.329 0.318 -0.011
TBR 0.325 0.294 -0.031
NYY 0.349 0.310 -0.039
OAK 0.321 0.296 -0.025
ATL 0.339 0.318 -0.021
CLE 0.337 0.310 -0.027
BAL 0.396 0.350 -0.046
PIT 0.387 0.337 -0.050
DET 0.428 0.340 -0.088
SFG 0.395 0.297 -0.098
MIN 0.413 0.313 -0.100
TOR 0.478 0.322 -0.156
CHW 0.442 0.315 -0.127
PHI 0.440 0.326 -0.114
KCR 0.469 0.336 -0.133

Recall that in 2017, St. Louis ranked dead least in terms of net wOBA. While the Cardinals’ bullpen was slightly above average that year, it certainly was not the second best in baseball like it was this season. The Cardinals’ rotation also performed better, supporting the groundbreaking hypothesis that have good pitchers makes managing easier.

Let’s also take a look at how many runs–and wins–the above values actually translated into.

To compute raw run values I turned to wRAA, which measures total offensive value. (wOBA works on a per-plate-appearance basis, not crediting managers who make fewer mistakes to begin with.) From there I could find the win value of a manager’s starting pitcher hook by using the 2017 cost of a win: 10.057 runs.*

*In 2019, this figure was 10.296 runs-per-win

Managerial “hook value” by team

Team SP TBF Runs "saved" Wins "added"
Team SP TBF Runs "saved" Wins "added"
WSN 84 10.16 0.99
MIA 72 9.96 0.97
BOS 64 4.65 0.45
CHC 91 4.48 0.44
LAD 85 2.35 0.23
COL 62 2.09 0.20
NYM 105 2.00 0.19
ARI 50 1.73 0.17
SDP 67 1.33 0.13
TEX 85 1.32 0.13
LAA 19 1.25 0.12
SEA 45 0.66 0.06
STL 75 0.65 0.06
HOU 69 -0.24 -0.02
MIL 47 -0.41 -0.04
CIN 88 -0.61 -0.06
MLB Avg. 68 -0.65 -0.06
TBR 38 -1.02 -0.10
NYY 45 -1.52 -0.15
OAK 72 -1.56 -0.15
ATL 96 -1.74 -0.17
CLE 80 -1.87 -0.18
BAL 52 -2.07 -0.20
PIT 71 -3.07 -0.30
DET 53 -4.03 -0.39
SFG 56 -4.74 -0.46
MIN 63 -5.45 -0.53
TOR 50 -6.74 -0.65
CHW 63 -6.92 -0.67
PHI 93 -9.16 -0.89
KCR 96 -11.04 -1.07

Some takeaways from this table:

  • Keep in mind that the wins “added” column is a very rough estimate, since it doesn’t take into account that these are high leverage plate appearences.
  • The Cardinals allowed their starting pitchers to remain on the mound the 11th most frequently, still a significant step up from ranking second highest over the course of Matheny’s tenure.
  • On the aggregate, managers are getting better! While still at an average negative value, they cost their teams about a run less than two seasons ago.
  • As the astute reader will notice, Kansas City finished last on both lists, even without–well, you know. On the bright side, Royals fans: it can’t get any worse than it already is.