Grading the Bullpen

With an off day on Monday coinciding with the end of April, plenty of Twins bloggers took the opportunity to recap the season so far. Given their excellent work, and the ongoing This Week in Twins feature written by Andrew Berg here at MNSG (which is always worth the read), I won't throw my hat in that ring, but rather we're going to take a more focused look at one aspect of the Twins ballclub, the bullpen.

Coming into this season, the Twins starting rotation was a sizeable question mark, but the bullpen was considered to be a strength. Juan Rincon, Pat Neshek, Jesse Crain, Dennys Reyes, Matt Guerrier, and one of the best closers in the game Joe Nathan were all returning pieces from a very solid bullpen last year. Glen Perkins started the year in AAA Rochester, but was quickly called up to provide an extra arm for Ron Gardenhire out of the pen. The Twins starters have averaged just over 6 innings per start, and at least one member of the bullpen has appeared in every game thus far this season, pitching 77 innings in 26 games. Given the importance of the bullpen and its perceived strength, let's take a look at how they are performing thus far.

Here are some selected stats for the Twins bullpen, listed alphabetically by middle initial (WXRL and Leverage stats are current through the weekend series):

PITCHER	G	IP	ER	H	BB	SO	WHIP	WXRL	Lev	K/9	BB/9
Jesse A. Crain	10	10.0	7	10	2	5	1.20	-0.161	1.57	4.5	1.8
Pat J. Neshek	12	12.0	3	6	4	12	0.83	0.969	1.06	9.0	3.0
Juan M. Rincon	11	10.2	2	10	8	14	1.69	0.182	1.64	11.8	6.8
Joe M. Nathan	12	12.1	3	16	4	12	1.62	0.899	2.04	8.8	2.9
Matt O. Guerrier	11	16.0	4	6	4	8	0.63	0.739	0.83	4.5	2.3
Dennys V. Reyes	15	7.2	6	13	7	7	2.61	-0.143	1.00	8.2	8.2
Glen W. Perkins	6	8.1	4	7	6	7	1.56	-0.002	0.63	7.6	6.5

First a word on the grades that you're about to see. I started everyone off at a C, and then, for a good performance, I bumped them up, and conversely, for a bad performance the overall grade dropped. I'm an optimist by nature, so I've tried to keep that in check a little bit by using Win Probability Added (which can be found at FanGraphs for each game) to settle any borderline performances.

Jesse A. Crain

Highest WPA - 4/3 vs. Bal, entered with Twins leading 3-2 with 2 outs and runners on 2nd and 3rd, faced a single batter, inducing a flyout to end the inning
Lowest WPA - 4/29 @ Det, entered a 3-3 tie, and, after one scoreless inning, gave up the game winning homerun to Brandon Inge

Recently Crain has certainly struggled. He was on the mound when the Indians broke a 3-3 tie in the 12th by scoring 4 runs (all charged to Jesse), and he also gave up Brandon Inge's walk-off homerun on Sunday. Perhaps these struggles are a result of a shoulder strain which kept him out for seven games (WPA before 24.5 in 4 games, WPA after -31.4 in 7 games). He's been used in high leverage situations, only Joe Nathan and Juan Rincon have a higher leverage index, and has done relatively well when brought into pressure situations. He has only allowed 1 of his 6 inherited runners to score (that was in the Yankees series with the Twins already trailing 6-0). He also hasn't got into too many jams, he's finished every inning he's started except the aforementioned debacle against the Indians in the 12th.

His WXRL is the lowest on the team thus far, and he hasn't really given us much to be optimistic about recently. Hopefully his shoulder will get back to full strength and his early season form will return.
Ray's Grade: C- (his early success keeps this from being lower)

Pat J. Neshek

Highest WPA - 4/23 vs. Cle, entered a tie game with the bases loaded and 2 out and retired the first batter with a strikeout. He also added another scoreless inning in the outing.
Lowest WPA - 4/19 @ Sea, entered with the Twins leading 6-2. Pat allowed a hit, a walk, and a homerun in 2/3 of an inning.

Neshek has been outstanding, the only runs he has allowed this year were on the homerun in a game where it made very little difference in the outcome of the game. He has inherited 8 runners and not allowed any of them to score. At no point has Neshek left the game with runners on base. The first batter Neshek has faced is hitting .111/.250/.222 with 4 strikeouts in 12 plate appearances, while with runners on base the numbers are similar, .136/.174/.318.

Neshek is one of two Twins relievers with a WHIP below 1.00, he has the highest WXRL of the bullpen. Oddly, his leverage index is hovering around 1. I would predict that number to come up as Gardenhire uses Neshek in more pressure packed situations with his continued success.
Ray's Grade: A-

Juan M. Rincon

Highest WPA - 4/26 v. KC, entered a 0-0 tie and pitched a 1-2-3 inning.
Lowest WPA - 4/12 v. TB, entered with a 2-0 lead, pitched 1/3 of an inning allowing a homerun, two singles, and a walk, allowing the Rays to tie the game before Neshek bailed him out.

It's difficult to asses Rincon, because even his good outings just aren't that inspiring, he's only had two outings where he hasn't allowed a baserunner. Rincon has the second highest leverage index in the bullpen behind Joe Nathan, he's pitched marginally well in pressure situations. His WPA is hurt by the very bad outing versus Tampa (-50.5 WPA) which counters his other 10 appearances (+51.4 WPA) of which the lowest is -1. He has allowed 3 of the 5 runners he has inherited to score and on 3 different outings other members of the bullpen have saved his bacon, of the 5 runners the bullpen has inherited from Rincon, none of them have scored.
Ray's Grade: B- (not enough positive outings to improve this too much)

Joe M. Nathan

Highest WPA - 4/26 v. KC, entered 0-0 tie and pitched two scoreless innings
Lowest WPA - 4/15 v. TB, entered 4-4 tie, allowed hits to the first three batters and took the loss, allowing two runs.

Other than back-to-back rough outings against Tampa Bay, Joe Nathan has been very good this year. Of course, we've come to expect nothing less. Nathan's numbers aren't quite what we are used to however. Opposing batters are hitting .320/.370/.420 against him including .345/.367/.414 with runners on base. When entering with a lead (8 games) Nathan has only allowed one run and racked up 36.7 WPA, compared to -37.6 WPA in the other 4 games.

Obviously, I'd like to see Nathan's WHIP come down some, but overall, as long as he continues to be lights out with the lead, I'll be happy. The other concerning stat I came across is that Nathan has thrown by far the most pitches of any of the relievers (222, next closest was 195 by Neshek in the same amount of innings) so that will definitely be something to watch for going forward.
Ray's Grade: B

Matt O. Guerrier

Highest WPA - 4/26 vs. KC, entered a 0-0 tie with runners on 2nd and 3rd with 2 out. He retired the first batter he faced, and added two more scoreless innings.
Lowest WPA - 4/20 @ KC, entered with Twins trailing 7-6. Allowed a homerun in his first inning, then allowed the first two batters to reach (single, hit by pitch) in his second. Rincon and Reyes allowed both of those runners to score.

Guerrier has been the surprise of the bullpen thus far this season. Originally expected to be an innings eater, he's pitched so well that we've started to see him in more important situations. In contrast to Joe Nathan's 18.0 pitches per inning, Guerrier has breezed through his appearances at 12.5 P/IP. Matt has the second highest WPA of the Twins bullpen, and has not allowed any of his six inherited runners to score (including 4/18 @ Sea, when he entered with the bases loaded and one out and got out of it with a strikeout and a flyout).

Essentially Guerrier has done everything asked of him. He has a higher WXRL than Reyes, Rincon, and Crain despite having a much lower leverage index. That WXRL is due to nothing more than excellent pitching. He has the lowest WHIP of the relievers and he has finished every inning except the one outing in Kansas City.
Ray's Grade: B+

Dennys V. Reyes

Highest WPA - 4/12 v. TB, entered with the Twins leading 2-0 with a runner on second with 2 out. Reyes retired the only batter he faced with a strikeout.
Lowest WPA - 4/18 @ Sea, entered with the Twins leading 5-3 with runners on first and second with 1 out. Reyes loaded the bases with a single to the only batter he faced. Matt Guerrier came in and got out of the jam (see above).

Reyes has not been good. It's not fair to compare to his numbers last year, because that was a career year for almost any reliever, but regardless, he has had 3 outings where he didn't record an out, and 12 of 15 outings he's allowed a runner to reach base. The rest of the bullpen has inherited 17 runners from Dennys and only allowed one to score. On the plus side, while Dennys was on the mound he hasn't allowed any of his 8 inherited runners to score.

His WHIP is outrageous, but perhaps more disturbing is the performance of Reyes against the first batter he faced in his appearances. They are hitting .500/.600/.833! This is not what you want to see from someone who comes out of the bullpen usually with the purpose of getting one or two batters.
Ray's Grade: F

Glen W. Perkins

Highest WPA - 4/23 v. Cle, entered trailing 3-0. Pitched 2.1 scoreless innings as the Twins tied the game.
Lowest WPA - 4/20 v. KC, entered trailing 5-4 with a runner on first and 1 out. He allowed that runner to score as well as one more, giving up 3 hits and a walk.

Perkins hasn't pitched poorly, but he certainly hasn't wowed anyone either. His WXRL and leverage tell the story, Glen Perkins has been a replacement level pitcher, used in situations that call for a replacement level pitcher. He has walked a batter in five of his six outings, which is something that needs to change for Perkins to become an effective pitcher.
Ray's Grade: C

Those are my grades. Seth, over at Seth Speaks, has also assigned grades to all the Twins players for April, including the bullpen. Here's how my grades stack up with his. The weighted GPA (4.0 scale) takes into account the number of innings pitched and the leverage index so that those who pitched more innings in pressure situations have grades that count for more.

PITCHER	Ray's Grade	Seth's Grades
Jesse A. Crain	C-	D
Pat J. Neshek	A-	A-
Juan M. Rincon	B-	B+
Joe M. Nathan	B	C+
Matt O. Guerrier	B+	B+
Dennys V. Reyes	F	F
Glen W. Perkins	C	C-
Bullpen GPA	2.33	2.19
Weighted GPA	2.58	2.40

From the weighted GPA, the overall grade for the bullpen thus far is a B-. That seems a little bit low given that this is still viewed as one of the best bullpens in the majors. Perhaps it's an indication of the high expectations that come along with the previous success of this bullpen. Those are my thoughts on the Twins bullpen. Where do you disagree? Was I too harsh? too lenient? Let me know in the comments.