Who Should Close for the Diamondbacks?

AJ Puk | Photo by Chris Arjoon/Getty Images

I’m not sure the Diamondbacks need a closer because it’s more important to reliably pitch well in high leverage situations. I’ll call the high leverage pitcher the muscler/fireman. After the muscler/fireman is chosen, then the closer can be chosen. So, the revised questions are, “Who should be the muscler?, and “Who should be the closer?”

Let’s look at last seasons relievers for the Diamondbacks. Let’s screen out candidates who should not be the muscler or the closer.

First Screen: Candidates will be Diamondbacks relievers who pitched at least 30 innings last season. After that screen there were eight pitchers.

Second screen was an ERA less than 4.00. That screen eliminated Scott McGough (7.44 ERA) and Paul Sewald (4.31 ERA). I do not expect them to return to the Diamondbacks. Six candidate pitchers remained.

Paul Sewald accounted for only 4 of the Diamondbacks’ 26 blown saves. Those 26 blown saves were the 8th most in the Majors. — Makakilo
After 1 July, [Paul Sewald’s] performance fell. Nine times he entered a game with the Diamondbacks ahead, no baserunners, and with leverage greater than 1. Three times he allowed zero runs and earned three saves. In the other six games he allowed a total of 10 runs, while leaving 2 runners on base. — Makakilo

Third Screen. Their Got-The-Job-Done (GTJD) was at least 67.7%. GTJD means no earned runs and no inherited runners scored. The following table shows the six candidate pitchers’ GTJD. This screeen eliminated Bryce Jarvis from consideration. AJ Puk’s GTJD was much better than the others. With the Marlins, his GTJD was 81.3% (excluding his 4 games as a starter). With the Diamondbacks, his GTJD was 90.0%.

Who would be best in the two roles?

Five candidates remain: AJ Puk, Joe Mantiply, Justin Martinez, Kevin Ginkel, and Ryan Thompson.

Addendum to add sixth candidate. Yesterday, the Diamondbacks claimed Seth Martinez on waivers. He passed the screens (3.59 ERA in Majors, 1.46 ERA in AAA, 68.2% GTJD in Majors, 84.6% GTJD in AAA).

To find the best Muscler/Fireman, let’s look at the sum of win probability added (WPA) for high leverage games (Li>1).

The following table shows that for high leverage games, AJ Puk had the most win probability added. He is left-handed.

When the Diamondbacks acquired AJ Puk, this AZ Snake Pit article noted he has a closer mentality, but he might not close. More than a closer, the Diamondbacks need a pitcher who can pitch well in high leverage situations. My view is AJ Puk is that pitcher.

Matchups are important. The right-handed pitcher with the highest WPA was Ryan Thompson. He could enter the game instead of AJ Puk when he would be a better matchup.

To find the best closer, let’s look at the sum of win probability added (WPA) for all games (high leverage and low leverage).

The following table shows that Joe Mantiply ranked second behind AJ Puk in WPA for all games. Interestingly, he also ranked second behind AJ Puk in WPA for high leverage games and his GTJD. Last season, he pitched in the ninth in 8 out of 75 appearances. Although he may be adverse to being the closer, he is worthy.

Joe Mantiply is left-handed. Matchups are important. More than the numbers, my intuition tells me that Justin Martinez (right-handed pitcher) could enter the game instead of Mantiply when he would be a better matchup. Justin Martinez pitched in the ninth about twice a s much as Joe Mantiply.

An additional factor backing up Justin Martinez as a closer was his good defense. More specifically his stolen bases per inning tied with AJ Puk. Also, it looks like he has the best range of the candidates.

The following table looks at DRS, controlling the running game, and fielding the ball.

Summary.

So, the revised questions are:

Who should be the muscler/fireman?
Who should be the closer?

Candidates from last season were screened to five pitchers: AJ Puk, Joe Mantiply, Justin Martinez, Kevin Ginkel, and Ryan Thompson. In addition, Seth Martinez, who was acquired on waivers, passed the screens.

Muscler/Fireman. The best reliever in high leverage situations was AJ Puk. he gets the nod for muscler/fireman. To give Torey Lovullo matchup choices, right-handed Ryan Thompson could enter the game to provide a better matchup.

Closer. There was no clear choice. Joe Mantiply (who rarely pitched in the ninth) was worthy of being considered, as was Justin Martinez. They are interesting ideas more than definite answers to the question.