The Brewers’ Healthy, Stealthy Starting Rotation

The Milwaukee Brewers have been one of the best stories of the season’s first half. They were picked by virtually no one to win the National League Central, and though it’s far too early for any hardware to be awarded, there are reasons galore for the club’s success to date. The team is exceptionally strong up the middle, offensively and defensively, thanks to the cost-controlled group of Jonathan Lucroy, Jean Segura, Scooter Gennett and Carlos Gomez. Their lineup is balanced and strong, with five players between 11 and 14 home runs and between 40 RBI and 49 RBI entering Monday night’s action. They also are quite athletic, with above-average team speed and defense; plus the bullpen has been effective all season. Their stealth strength, though, just might be their healthy, durable starting rotation that has a very good chance to boast five ERA qualifiers this season — a trait that’s much more central to winning than you might think.

All but one of the Brewers’ games this season have been started by the five men in their season-opening rotation: Kyle Lohse, Matt Garza, Yovani Gallardo, Wily Peralta and Marco Estrada. Barring injury or a performance flameout, Milwaukee seems to be on track to have five ERA-title qualifiers this season, with Estrada — the guy with the lowest innings total to date — only 60 innings away from qualification. How often do clubs reach this benchmark, and what might it mean for their seasonal team performance? Below is a list of all of the clubs with five ERA qualifiers, going back to 2000.

YR	TM	WINS	#1	IP	#2	IP	#3	IP	#4	IP	#5	IP
2013	DET	93	Verlander	218.33	Scherzer	214.33	Fister	208.67	Sanchez	182.00	Porcello	177.00
2012	CIN	97	Cueto	217.00	Latos	209.33	Bailey	208.00	Arroyo	202.00	Leake	179.00
2012	SF	94	Cain	219.33	Bumgarner	208.33	Vogelsong	189.67	Lincecum	186.00	Zito	184.33
2011	TEX	96	Wilson	223.33	Lewis	200.33	Holland	198.00	Harrison	185.67	Ogando	169.00
2010	TB	96	Price	208.67	Garza	204.67	Shields	203.33	Niemann	174.33	Davis	168.00
2008	LAA	100	Santana	219.00	Saunders	198.00	Garland	196.67	Weaver	176.67	Lackey	163.33
2006	CWS	90	Garcia	216.33	Garland	211.33	Buehrle	204.00	Vazquez	202.67	Contreras	196.00
2005	CLE	93	Westbrook	210.67	Lee	202.00	Sabathia	196.67	Millwood	192.00	Elarton	181.67
2005	STL	100	Carpenter	241.67	Marquis	207.00	Mulder	205.00	Suppan	194.33	Morris	192.67
2004	BOS	98	Schilling	226.67	Martinez	217.00	Wakefield	188.33	Lowe	182.67	Arroyo	178.67
2004	OAK	91	Mulder	225.67	Zito	213.00	Redman	191.00	Harden	189.67	Hudson	188.67
2004	STL	105	Morris	202.00	Marquis	201.33	Williams	189.67	Suppan	188.00	Carpenter	182.00
2003	ATL	101	Maddux	218.33	Ru.Ortiz	212.33	Hampton	190.00	Ramirez	182.33	Reynolds	167.33
2003	SEA	93	Moyer	215.00	Franklin	212.00	Pineiro	211.67	Garcia	201.33	Meche	186.33
2002	BOS	93	Lowe	219.67	Martinez	199.33	Burkett	173.00	Castillo	163.33	Wakefield	163.33
2002	SF	95	Hernandez	216.00	Ru.Ortiz	214.33	Rueter	203.67	Schmidt	185.33	Jensen	171.67
2001	LAA	75	Rm.Ortiz	208.67	Schoeneweis	205.33	Washburn	193.33	Rapp	170.00	Valdez	163.67
2000	STL	95	Kile	232.33	Stephenson	200.33	Hentgen	194.33	Ankiel	175.00	Benes	166.00
	AVG	95

That’s a total of 18 clubs with five ERA qualifiers in 14 seasons, or a little more than one team per year. Every year is represented on the list except 2007 and 2009. Thus far in 2014, only the Brewers are on track to join the fraternity, though the Dodgers will join them as soon as Clayton Kershaw’s innings total reaches qualification status.

The most amazing thing about this group of clubs appears in the “wins” column. Seventeen of these 18 teams won 90 or more games in the season in which they had five or more ERA qualifiers. That’s far too high a percentage to be a fluke. These clubs averaged 95 wins, and cracked the 100-win barrier four times. The one club that failed to win 90 games, the 2001 Angels, was a massive outlier, winning only 75. But that club turned over 60% of its rotation and won the World Series the next season.

Perusing the list of names comprising the 18 rotations above, you find a whole lot of league average-ish pitchers: Jon Garland, twice. Jeff Suppan, twice. Bronson Arroyo, twice. The winningest team on the list rolled out Suppan, Jason Marquis and Woody Williams for about 60% of their contests. Mark Redman, Ryan Franklin, Scott Elarton — even Garrett Stephenson, Ryan Jensen and Frank Castillo — the gang’s all here. These are not superstar rotations. In fact, the vast majority of them feature two qualities above all else: competence and health. Rolling out your relatively unexciting, near league-average No. 5 starter 30 or more times isn’t sexy, but it beats the heck out of running out Nos. 6, 7, 8 or even 9. Ask the 2014 Texas Rangers how that’s working out.

On the surface, the Brewers group appears to be somewhat vanilla, giving the club some length innings-wise while pitching to contact more often and issuing free passes less often than your average rotation. Let’s take a closer look at the five hurlers’ 2014 plate-appearance outcome frequency and production by BIP type data to see how they get it done. First, the frequency information:

FREQ – 2014
Estrada	%	REL	PCT
K	20.5%	101	41
BB	7.8%	99	57
POP	14.0%	182	99
FLY	35.7%	128	99
LD	19.2%	92	10
GB	31.1%	71	1
———–	———-	———-	———-
Gallardo	%	REL	PCT
K	18.0%	89	19
BB	6.7%	85	47
POP	4.5%	59	7
FLY	28.6%	102	69
LD	17.2%	83	1
GB	49.7%	114	91
———–	———-	———-	———-
Garza	%	REL	PCT
K	18.4%	91	22
BB	7.4%	94	54
POP	9.8%	127	87
FLY	27.5%	99	58
LD	19.8%	95	16
GB	42.9%	98	28
———–	———-	———-	———-
Lohse	%	REL	PCT
K	17.8%	88	19
BB	4.7%	59	13
POP	9.1%	118	85
FLY	31.1%	112	86
LD	19.8%	95	16
GB	39.9%	92	21
———–	———-	———-	———-
Peralta	%	REL	PCT
K	17.7%	87	18
BB	6.2%	78	35
POP	6.7%	87	45
FLY	22.3%	80	2
LD	20.4%	98	28
GB	50.6%	116	92

Estrada has been the least successful member of the Brewer rotation this season, but you can’t tell from his frequency distribution. He is one of the most extreme popup/fly ball pitchers in the game today. The popups are a very good thing. His 2014 popup percentile rank of 99 is not a new development. His 13.6% popup rate ranked second to Oakland’s A.J. Griffin among 2013 ERA qualifiers. His fly ball percentile rank of 99, on the other hand, presents a significant amount of risk, as we’ll see in the next table. With so many popups and fly balls, his grounder percentile rank (1 in 2014) is obviously going to be quite low. His low liner rate (10 percentile rank) appears ripe for regression, however, as it had been above MLB average in two of the previous three seasons.

Gallardo’s frequency profile is interesting, with some significant trends in process. As recently as 2012, he had a K-rate percentile rank of 89, and that was his lowest since 2009. It now stands at 17, which means his days as a big strikeout guy might be over. On the positive side, his walk percentile rank of 47 is his second best since 2009, and he has evolved into a fairly extreme ground ball generator, with a 2014 percentile rank of 91. That’s far higher than his previous best of 76 in 2012. There are more negatives, though: He never induces a popup, as his percentile rank in that category has been in single digits for three consecutive seasons. Lastly, don’t believe in his very low 2014 liner rate (1 percentile rank). Gallardo’s liner rate has swung very high to very low from season to season, and his 2014 performance likely is not reflective of a true skill.

After six straight seasons with above MLB average K rates, Garza has seen his percentile rank drop to 22 in this category. He has always possessed a fly ball tendency, but in 2014, they have been hit higher than in previous years, as his popup percentile rank has spiked to 87, his highest since 2008. Like Estrada and Gallardo, however, Garza’s 2014 liner percentile rank is very low (16) and does not appear to be reflective of a true skill, as it has been 70 or higher in three of the previous four seasons. Garza’s liner rate also appears poised for some regression.

Lohse is the purest pitch-to-contact guy of the group, with K and BB percentile ranks of 19 and 13, respectively. Like Estrada – though not as extreme – and to a lesser extent Garza, Lohse is a popup/fly ball generator, and his 85 and 86 percentile ranks in those categories are his highest going back to 2008. Once again, however, his liner percentile rank of 16 is quite low compared to his track record, and appears due for some near-term regression.

Peralta is yet another pitch-to-contact hurler, and his most positive 2014 development has been the significant decline in his walk rate — from a 2013 percentile rank of 82 to a 2014 percentile rank of 38. He’s evolving into a fairly extreme ground-ball generator, as his percentile rank in that category has climbed from 77 in 2013 to 92 this year. His liner rate is also well below MLB average (28 percentile rank), though it’s too early in his career to determine whether this is a skill or a fluke.

As a group, the Brewer starters don’t hurt themselves with walks, but they also don’t miss a lot of bats. The most interesting observation gleaned from the frequency tables might be the low liner rates generated in the season’s first half, and the potential regression that could loom as we head down the stretch.

Next, let’s look at the production by BIP type allowed by all five pitchers this season, both before and after adjustment for context:

PROD – 2014
Estrada	AVG	OBP	SLG	REL PRD	ADJ PRD	ACT ERA	CALC ERA	TRU ERA
FLY	0.324		1.078	182	129
LD	0.655		0.891	101	103
GB	0.236		0.258	95	91
ALL BIP	0.316		0.643	126	109
ALL PA	0.244	0.304	0.496	119	105	4.94	4.52	3.97
————-	———-	———-	———-	———-	———-	———-	———-	———-
Gallardo	AVG	OBP	SLG	REL PRD	ADJ PRD	ACT ERA	CALC ERA	TRU ERA
FLY	0.273		0.716	96	111
LD	0.642		0.811	91	118
GB	0.229		0.235	85	87
ALL BIP	0.303		0.459	86	100
ALL PA	0.241	0.296	0.365	88	100	3.45	3.32	3.79
————-	———-	———-	———-	———-	———-	———-	———-	———-
Garza	AVG	OBP	SLG	REL PRD	ADJ PRD	ACT ERA	CALC ERA	TRU ERA
FLY	0.204		0.473	46	67
LD	0.687		0.910	108	88
GB	0.228		0.255	91	76
ALL BIP	0.290		0.428	77	74
ALL PA	0.232	0.289	0.343	81	78	3.78	3.07	2.96
————-	———-	———-	———-	———-	———-	———-	———-	———-
Lohse	AVG	OBP	SLG	REL PRD	ADJ PRD	ACT ERA	CALC ERA	TRU ERA
FLY	0.221		0.540	58	72
LD	0.639		0.875	96	106
GB	0.234		0.248	91	121
ALL BIP	0.288		0.442	79	96
ALL PA	0.234	0.270	0.358	78	93	3.18	2.94	3.51
————-	———-	———-	———-	———-	———-	———-	———-	———-
Peralta	AVG	OBP	SLG	REL PRD	ADJ PRD	ACT ERA	CALC ERA	TRU ERA
FLY	0.329		0.973	161	126
LD	0.612		0.761	81	99
GB	0.265		0.271	114	101
ALL BIP	0.327		0.502	101	98
ALL PA	0.264	0.311	0.404	101	97	3.35	3.84	3.69

The actual production allowed by each hurler on each BIP type is indicated in the AVG and SLG columns, and is converted to run values and compared to MLB average in the REL PRD column. That figure is then adjusted for context, such as home park, team defense, luck, etc., in the ADJ PRD column. In the three right-most columns, the actual ERA, calculated component ERA based on actual production allowed, and “tru” ERA, which is adjusted for context, are all presented. For the purposes of this exercise, SH and SF are included as outs and HBP are excluded from the OBP calculation.

Estrada has obviously been hammered in the air this season, allowing 26 homers already, and a hefty REL PRD figure of 182 on fly balls. That matches the MLB-leading mark posted by Edinson Volquez in 2013. Like Volquez, though, adjustment for context works wonders: Miller Park is fly-ball-friendly, and Estrada has allowed more than his share of less than solidly hit homers this season. His fly ball ADJ PRD figure of 129 will still rank near the top of the league but it is at least survivable. His liner and grounder authority allowed (percentile ranks of 91 and 103) are in the league-average range. His ADJ PRD on all BIP — his “adjusted contact score” — is within hailing distance of league average at 109. His “tru ERA” of 3.97 is about a full run better than his actual mark. He’s allowing top-of-the-scale homer totals, but he is still viable, thanks primarily to his massive popup rate.

Gallardo, on the other hand, has been fairly fortunate on balls in play this season, as his ADJ PRD is higher than his REL PRD on all BIP types. Though his REL PRD — his unadjusted contact score — is a solid 86, it is adjusted upward for context to 100, which is exactly league average. His near league average K and BB rates don’t move the needle at all, and his “tru” 3.79 ERA matches the current MLB average.

Garza, despite possessing the second highest actual ERA of the group, is clearly the Brewers’ best starter this season. He has done an exceptional job suppressing fly ball authority — his REL PRD of 46 and ADJ PRD of 67 on flies would have ranked at the elite level among 2013 ERA qualifiers. He has allowed better than league-average liner and grounder authority, and his adjusted contact score of 74 would have led the NL in 2013. His slightly subpar K and BB rates bump his overall ADJ PRD up to 78, but his “tru” ERA is quite strong at 2.96, 0.82 lower than his actual mark.

Lohse has suppressed fly ball contact nearly as well as Garza, with an ADJ PRD of 72 on flies. Lohse has allowed harder than league-average line drive and grounder contact (ADJ PRD of 106 and 121), and his unadjusted contact score of 79 is therefore adjusted upward from 79 to 96 for context. His very low BB rate drops his overall ADJ PRD down to 93, for a “tru” ERA of 3.51, a bit above his actual 3.18 mark.

Peralta doesn’t allow that many fly balls, but the ones he does allow are hit quite hard, as his ADJ PRD of 126 on flies is in Estrada territory. His liner and grounder ADJ PRD figures are squarely in the league-average range, and his high grounder rate allows him to post an overall adjusted contact score of 98 despite the hard fly ball contact. His near average K/BB performance barely changes his overall ADJ PRD figure to 97, for a “tru” ERA of 3.69 that is a bit above his actual 3.35 mark.

The one thing that is hard to discern from the table above is the impact of each pitcher’s low liner rate upon their “tru” ERAs. Upward regression of their liner rates would push their “tru” ERAs upward, so mentally adjust those marks marginally going forward. Still, what we have here is a group of average to slightly above average starting pitchers, with Garza potentially a bit better than that. Call Garza a #2-3 starter, Lohse/Peralta/Gallardo #3-4 starters, and Estrada a #4. Peralta is trending up, Gallardo down, the others are what they are. They lack a true ace, but if you can run out five #4 or better starters every single day over a 162-game season, you’ve got something, and have a decent chance of extending your season into October.

So what happens when October rolls around? Well, only two of the 18 clubs with five ERA-qualifying starters since 2000 have won it all. Starting rotation depth matters a lot less in the postseason, when rotation top-heaviness matters a whole lot more. Still, getting there is the first and hardest step in the process. The Brewers have many strengths, but the team also has weaknesses that could bite them at some point. Chief among them is a lack of upper-level depth that could become an issue if injuries strike any of the team’s four or five top regulars, any rotation member or one of the back-end relievers. The Cardinals, Pirates and Reds are all lurking, and they likely have the Brewers beat when it comes to roster spots 26 through 35. Still, regression does not impact the lead the Brewers already have or the stats they’ve already compiled. They are in a strong position for the rest of the season, due in large part to a steady but unspectacular band of starting pitchers, men who are more akin to bass players than lead singers or guitarists.