A third pillar of bullpen management for the Mets

If you asked fans of all 30 MLB clubs what they thought of their bullpen, most probably wished it was better. So far under Buck Showalter, the Mets’ pen has been run much better than it has been in ages. It’s no exaggeration to say it’s better than it has been in at least a decade. Showalter understands better than (at least) the previous three Mets managers to pilot a game the need for rest, that one day off doesn’t automatically refresh a guy regardless of how many days he’s pitched previously. No longer do we consistently see a reliever having pitched in three of the last four games.

That may not sound like much but it is. We should always celebrate when improvement has been made and all Mets fans should recognize the step forward that’s been made this season. Hooray for Showalter.

My preference in running a bullpen is to carry multiple relievers capable of going two or three innings at a time. It’s clear that Showalter is not utilizing his relievers that way. But that’s just not the way the game is managed in the 21st Century. Understanding that most every reliever nowadays is a short reliever, my new preference is to get the relievers a clean inning. That is, bring them on and use them at the start of an inning and have them go the full frame. In the past, my twin pillars of bullpen management were leverage and rest. Now let’s introduce a third pillar – the minimization of mid-inning pitching changes.

You’re never going to be able to eliminate mid-inning pitching changes. But you can absolutely cut down on the number of times you switch relievers in an inning. In Saturday night’s game, the Mets made two mid-inning switches. The first was when Chris Bassitt was removed after 5.2 IP and the second was when Chasen Shreve came on with two outs in the seventh.

If you ran your pen with the idea of reducing mid-inning changes, you never would have had Bassitt start the sixth inning. Bassitt worked really hard to get out of the fifth inning and his pitch count was high. On one hand, it was nice to see Showalter not so eager to remove his starter. But it was a cold, rainy night and Bassitt was succeeding without cruising. This wasn’t a case of a guy who struggled early but had found his stride.

And if Showalter had gone to his pen at the beginning of the sixth inning, odds are his relievers would have been in a better situation. Seth Lugo was the first reliever Showalter used. Lugo got out of the sixth without any further runs. But he came back in the seventh and only pitched a partial inning. And Shreve came on in a mid-inning change and ended up giving up a 3-run homer.

When Lugo comes on at the start of an inning and pitches the full frame, he’s gone 10 IP without allowing an ER. When Shreve comes on at the start of an inning and pitches the full frame, he’s gone 7 IP without allowing an ER. We never know how things are going to work out – we just know what eventually happens. And last night the Mariners ended up scoring all four of their runs in the two frames that had mid-inning pitching changes. Maybe they score four runs if Lugo starts and finishes the sixth and Shreve starts and finishes the seventh. We’ll never know. We do know those two individuals haven’t given up a run all season when they start and finish a frame.

Let’s do a chart of the Mets’ relievers this season and compare how they do when they start and finish a frame compared to how the do when they come on in the middle of an inning.

Reliever	Clean			Mid-Inning
	IP	ER	ERA	IP	ER	ERA
Trevor May	8	6	6.75	0.1	0	0.00
Adam Ottavino	10	0	0.00	2	3	13.50
Seth Lugo	10	0	0.00	3.1	4	10.80
Edwin Diaz	15	2	1.20
Drew Smith	12	1	0.75	1	0	0.00
Sean Reid-Foley	6	2	3.00	1.2	0	0.00
Joely Rodriguez	7	0	0.00	2.1	2	7.72
Chasen Shreve	7	0	0.00	4	1	2.25
David Peterson	4	0	0.00
Adonis Medina	3	0	0.00	0.2	0	0.00
Yoan Lopez	3	3	9.00
Trevor Williams	6	2	3.00	3	1	3.00
Stephen Nogosek	3	0	0.00
Totals	94	16	1.53	18.1	11	5.40

It’s pretty easy to see why one should have a preference for clean innings. It’s hard to imagine a bigger edge than nearly four runs per nine. And this doesn’t even include the inherited runners that score in mid-inning changes. Mets relievers have inherited 33 runners so far this season and 14 of those have scored. That’s a ratio of 42% of IR to score. This is a metric where the lower, the better. MLB average is 33% so the Mets are doing poorly in this category. The Rays lead the majors with a 17% IR to score and the Mariners are second with a 19% rate.

However, this isn’t a perfect comparison as there is a “survival bias” built into the numbers for clean innings. May and Lopez aside, there are times when a reliever starts off an inning with a chance to go 1 IP, 0 ER, he’s not pitching well and gets pulled before he completes the inning. On the flip side of that is a pitcher doing fine and gets pulled mid-inning to get the platoon advantage. Both of those cases are included in the mid-inning numbers above but not the clean innings.

But, if chasing the platoon advantage mid-inning is a worthwhile gambit, and relievers have a 5.40 ERA with that included – that really shows why a team would benefit from getting clean innings whenever possible. Especially when the gambit fails like it did Saturday night. Shreve gives up the homer to the LHB but only one of the three runs goes on his ERA. The other two were inherited runners that scored and went on the previous pitcher but not reflected in the above chart.

Since Lugo was the pitcher last night who had the runners he left on base score when he pitched a partial inning, let’s use him as an example of the partial innings not included in the above chart. He has 4 ER combined when he enters and finishes with a clean inning and when he enters the game mid-inning. But he has 6 ER on the season. Maybe he would have given up both runs Saturday night (and possibly more) if he pitched the full inning. Or maybe he would have gotten out of it without any runs scoring.

The numbers from the chart above show the relievers allowing 27 earned runs. Mets relievers this year have allowed 45 earned runs, meaning we have 18 out there to relievers who started an inning and didn’t finish. That’s not good. We know 14 of those were inherited runners that the subsequent reliever allowed to score, which means we have at least four runs that were the direct responsibility of the reliever who started the frame but didn’t finish. We say at least because the chart is looking at earned runs and not total runs. Mets’ relievers have allowed two unearned runs so far this year so it’s not enough to move the needle very much in any direction.

If we assume that the relievers who started the inning but did not finish and did not have their work show up in the above chart would give up all of the runs that the subsequent relievers did, what would the new “clean” numbers look like?

We have the clean innings so far at 94 IP and 16 ER. Add in the mid-inning results of 18.1 IP and we have 112.1 IP accounted for in our chart. Mets relievers have thrown 118.1 IP so far this year, so we have a combined total of 6 IP where a reliever starts an inning and doesn’t finish. Earlier we determined that there were 18 ER unaccounted for in our chart. So, if we add 6 IP and 18 ER to our clean total, we get 100 IP where a reliever started an inning, along with 34 ER.

So, when a reliever on the 2022 Mets starts an inning clean, he has a 3.06 ERA.
When a reliever comes on mid-inning for the Mets this season, they have a 5.40 ERA. And that’s not counting the 14 inherited runners they allowed to score.

In the Game Chatter last night, I said that the Mets shouldn’t have let Bassitt pitch the sixth inning. He gave up a run before Lugo finished the frame. But when Lugo came out for the seventh – an up/down in the current parlance – he wasn’t allowed to finish the inning and had the next reliever allow two runs to score that were charged to his record.

The up/down has been an issue all season. Back in April we identified the Perverse Platoon Ploy, when Showalter brought a reliever back in an up/down to get the platoon advantage. In four instances at the time that was written, the reliever came back from the up/down to put five runners on base without recording an out. All five scored and in total 13 runs came in those four innings.

As stated earlier, you’re never going to be able to eliminate mid-inning pitching changes. But last night was not the time to push Bassitt and those four instances in the above graph are definite examples of mid-inning changes that could easily have been avoided.

Showalter has run a good pen so far this season. If he would make it an emphasis to get his relievers clean innings, it would be a great pen. So, let’s continue to get away from matchups against non-elite hitters. And let’s run the pen on the tri-pillars of leverage, rest and full, clean innings.