Should the Mets have kept Dan Warthen?

Since the end of the 2010 season, the Mets have overhauled their front office, made a managerial change and reassigned some coaches, including batting coach Howard Johnson. But one area that remains unchanged is the pitching coach. The new Mets brain trust decided to retain Dan Warthen, who has been in charge of the team’s pitchers since taking over for Rick Peterson in June of 2008.

Was this a good decision?

Under Warthen, the Mets finished sixth in the National League with a 3.73 ERA last year. Also, Warthen generally has the support of his pitchers. Both R.A. Dickey and Mike Pelfrey are on record supporting his return, with Pelfrey telling the New York Daily News near the end of the season:

“If it was up to me, I would bring him back. He’s a very good communicator. I would love to see him back. I’ve already been through two (including former pitching coach Rick Peterson), and it would be nice to have the same guy back that you have a relationship with that you could continue to build on.”

On the surface, sixth in ERA sounds pretty good, especially for a team that finished below .500 on the year. But how much of that was due to Citi Field? As a team, the Mets had a 3.12 ERA at home last year, compared to a 4.36 ERA on the road. The Mets ranked 12th in the National League in road ERA in 2010.

Plus, it’s nice that Warthen communicates with his players, but I would rather that he teach them something concrete or do something to keep his pitchers healthy. At least 11 pitchers went on the disabled list for the Mets the past two years, not counting Johan Santana in 2010, who was injured in September after teams no longer use the DL.

Let’s compare Warthen to Peterson, the man he replaced and see the results of pitchers who threw at least 50 IP under both pitching coaches. The following chart shows IP and ERA for the six pitchers who meet the criteria, with Peterson’s results first and Warthen’s second.

	IP	ERA	IP	ERA
Santana	94.2	2.85	505.1	2.85
Pelfrey	164	4.99	519	4.09
Perez	286	4.28	234	5.23
Maine	362.1	3.83	179.2	4.86
Martinez	422.1	3.69	64.1	5.18
Feliciano	151.1	2.62	148.1	3.58

The only pitcher to do better under Warthen was Pelfrey, a young pitcher who should have been expected to improve as he got acclimated to the majors.

Let’s do another chart, this one comparing average fastball velocity in 2007, the last full year under Peterson, to 2010.

	2007	2010
Santana	91.7	89.4
Pelfrey	92.4	92.0
Perez	90.5	88.0
Maine	91.2	88.7
Martinez	86.2	—
Feliciano	86.6	87.0

The declining velocity of Santana, Perez and Maine has been a large part of their struggles. It can certainly be argued that injuries have robbed these players of their velocity but that goes back to the fact that Mets pitchers are getting injured under Warthen. The raw totals between Peterson and Warthen are similar but Peterson worked with an older staff that included Martinez and Orlando Hernandez.

When Peterson was the coach, Perez missed 18 days to the disabled list and Maine 37. Under Warthen Perez missed 119 days to the DL and Maine 285. Also, Santana has undergone surgery three straight years.

Perhaps all of these injuries would have occurred if Peterson remained the pitching coach. What we do know is that Peterson was fired and Warthen retained, when the pitchers that pitched significant innings under each performed better under Peterson and stayed healthier.

Right now, Warthen has two things to point to in his tenure with the Mets – Pelfrey and Dickey. Pelfrey, a former first-round draft pick, has been essentially a league-average pitcher under Warthen’s tutelage. Dickey reinvented himself with the knuckleball, a pitch that Warthen did not teach him. As far as success stories go, these are underwhelming.

Whose mechanics did Warthen overhaul for the better? Which pitcher learned a new pitch under Warthen? Who saw their command or stuff take a leap forward under Warthen? Who was able to stay healthy who was previously a DL resident? Which relievers turned in career years under Warthen?

No doubt someone will bring up Pelrey’s splitter. Disregarding the wisdom of teaching a splitter to a pitcher whose main pitch was a sinker, how effective was this pitch for Pelfrey? FanGraphs shows Pelfrey’s splitter being 3.9 runs below average last year. It was a great pitch in April, but once hitters knew it was part of his arsenal, it was dreadful.

Aw hell, let’s just do some research. Here are Pelfrey’s month-by-month numbers for his splitter. All numbers are runs above or below average:

April – 2.3
May – 0.4
June – (-1.8)
July – (-3.4)
August – 0.0
September – (-1.4)

So, from June 1st to the end of the year, Pelfrey’s splitter was 6.6 runs below average. This is not a feather in anybody’s cap. If anything, Pelfrey should scrap the splitter and work on a new pitch, either by himself or with someone else in the Mets organization, besides Warthen. Maybe he should be tutored by Ricky Bones, the pitching coach at Triple-A who is generally well-regarded.

So, what single thing can you say that Warthen has done to make the Mets pitchers better?

I have no doubt that Warthen is a great guy and that pitchers like his personality. What I fear is that Warthen is the pitching coach version of Jeff Francoeur – all personality and style and no production nor substance.

That the Mets’ housecleaning this year did not include Warthen was disappointing.