Are Greinke and Kershaw the Best Starting Duo Ever?

A brief break from politics to look at another towering issue of the day.

Zack Greinke and Clayton Kershaw each had brilliant seasons for the Dodgers in 2015, and their double-barreled dominance raises the question:  are they the best starting duo ever?  Furthermore, this is the second year in a row each has excelled.  Have we ever seen two starting pitcher teammates perform at such a level for consecutive seasons?

Let me give you the short answer and then work back to the analysis.  The Greinke/Kershaw duo certainly qualifies as one for the ages, and it does not disparage them at all to report that their 2015 performance ranks 7th on the list of best by a pair.  As for the consecutive season performance over 2014/15, you have to go back to 1906/07 to find a better one, and they rank third all-time.

I set up the analysis as follows.  I used “Adjusted ERA+” as the defining factor for determining greatness.  I think it is the single pitching statistic that best captures relative performance, in that it directly compares a pitcher’s ERA to that of his league, and also adjusts statistically for the ballpark factor (that is, for whether it is a hitter’s or pitcher’s park).  This makes it a good statistic to compare across eras, since it self-adjusts for lighter hitting eras (such as the ‘Dead Ball Era”) and those featuring more pop (like the 1930’s and the more recent “Steroids Era”).

I defined “starting pitcher” as one who had started at least 20 games in a season, appeared in over half their games pitched as a starter, and qualified for the ERA title.  I excluded the Federal League, all seasons before 1901, and any pitcher who was traded midseason.

And finally, I set a bar for each pitcher (in the pair) to have an ERA+ of 125 or more.  This was to avoid what I call the “Christy and Hank Mathewson Problem” (or, if you prefer, the “Henry and Tommie Aaron Problem”), in which one half of the partnership is so dominant that he drags along the other into historical greatness, rather undeservingly.  (Henry and Tommie Aaron hold the record for most homers by brothers, 768, of which Tommie hit only 13.)  The 125 was fairly arbitrary as a cutoff, but every year about 15-20 or so pitchers in MLB cross this threshold and that seemed a fine amount to define a “great season” (there were exactly 15 who did so in 2015).

Greinke alone had a spectacular season in 2015.  His ERA+ of 225 was tied for 13^th all time.  He had an ERA of 1.66 which was less than half of the National League ERA of 3.90.  Pedro Martinez’s wondrous 2000 season leads the pack, when he had an otherworldly ERA+ of 291, with an ERA of 1.74 when the American League, in the heart of the steroids era, had a league-wide ERA of 4.91.  You can see the Top 20 below, and note the legendary names (Johnson, Mathewson, Young, Maddux) and fabled seasons (Gibson, 1968; Gooden, 1985) that populate it.  I extended the chart to the Top 20 so that one notes the inclusion of Jake Arietta in 2015 as well.  Two stunning seasons by Greinke and Arietta, and 2015 thus joins 1997 as the only seasons to appear twice on this list.

Rank	Player	Team	Adjusted ERA+	Year
1	Pedro Martinez	BOS	291	2000
2	Dutch Leonard	BOS	282	1914
3	Greg Maddux	ATL	271	1994
4	Greg Maddux	ATL	260	1995
5	Walter Johnson	WAS	259	1913
6	Bob Gibson	STL	258	1968
7	Mordecai Brown	CHC	253	1906
8	Pedro Martinez	BOS	243	1999
9	Walter Johnson	WAS	240	1912
10	Christy Mathewson	NYG	230	1905
11	Dwight Gooden	NYM	229	1985
12	Roger Clemens	HOU	226	2005
13	Pete Alexander	PHI	225	1915
13	Zack Greinke	LAD	225	2015
15	Roger Clemens	TOR	222	1997
15	Christy Mathewson	NYG	222	1909
17	Jake Arietta	CHC	219	2015
17	Pedro Martinez	MON	219	1997
17	Cy Young	BOS	219	1901
20	Lefty Grove	PHA	217	1931

Let’s move on to teammates in one year.  I’ve listed the Top 10 below.  A pair of ancient names, Dutch Leonard and Rube Foster, top the list for the 1914 Boston Red Sox.  Leonard had a year that was just behind Pedro’s on the list above, and Foster was no slouch either with a 160 ERA+.  Remarkably, that Red Sox staff also featured a 20-game winner, Ray Collins, a youthful future Hall-of-Famer named Smoky Joe Wood, and a rookie who got in a few starts here and there, a big fella named George Herman Ruth.

Brown and his famous fingers

But the stars of this page are the Cubbies of another era, circa 1906-1908, who had three of the top five “pairs” of seasons because they had an incredible staff, not just a pair.  The most familiar name is Mordecai “Three Finger” Brown, so named for a farm accident that claimed a few of his digits, but also bequeathed to him, by virtue of the loss, a virtually unhittable curve ball.  Ed Reulbach, Jack Pfiester and Carl Lundgren excelled as well.   

You’ll note Pedro Martinez pairing with Bret Saberhagen for Boston in 1999; there is a quibble here because while Saberhagen, nearing the end of a brilliant, though injury-riddled career, pitched sensationally (ERA+ of 171), he made only 22 starts, just above my arbitrary threshold.  You may have thought that Randy Johnson and Curt Schilling of the 2001/12 Arizona Diamondbacks might make the list, but the 21st century National League pair that did was instead Roger Clemens and Andy Pettitte, in 2005 for Houston (asterisk fans, this is your moment).  Then comes Greinke and Kershaw, followed by Greg Maddux, Walter Johnson and Bob Gibson, all having historic seasons, partnered with excellent ones by Tom Glavine, John Boehling and Ray Washburn, respectively.

Rank	Teammates	Team	Adjusted ERA+ (1)	Adjusted ERA+ (2)	Adjusted ERA+ (Both)	Year
1	Dutch Leonard/Rube Foster	BOS	282	160	221	1914
2	Jack Pfiester/Carl Lundgren	CHC	216	213	215	1907
3	Mordecai Brown/Jack Pfiester	CHC	253	174	214	1906
4	Pedro Martinez/Bret Saberhagen	BOS	243	171	207	1999
5	Mordecai Brown/Ed Ruelbach	CHC	253	159	201	1906
6	Roger Clemens/Andy Pettitte	HOU	226	177	202	2005
7	Zack Greinke/Clayton Kershaw	LAD	225	175	200	2015
8	Greg Maddux/Tom Glavine	ATL	260	137	199	1995
9	Walter Johnson/Joe Boehling	WAS	259	138	199	1913
10	Bob Gibson/Ray Washburn	STL	258	129	194	1968

And that brings us to more sustained excellence, two teammates each accomplishing 125+ over two consecutive seasons.  I did this whole exercise in reverse chronological order, and I actually did this analysis first, before creating the charts above.  Greinke and Kershaw held their position at the top of the charts for decade after decade, soaring above (working back in time) Halladay, Lee and Hamels of the recent Phillies, Pedro and Clemens and their various pals, the Hudson, Zito, Mulder A’s, Johnson and Schilling, the Holy Trinity of Maddux, Glavine and Smoltz, Gooden and Darling, well beyond those Orioles staff of the early 1970’s, and Seaver and Koosman, and their Dodger forebears of Koufax and Drysdale, the legendary Indians of the 1950’s, as well as Spahn and Sain (no need to pray for rain), the Dean brothers, Lefty’s Grove and Gomez and their colleagues, and The Big Six Mathewson (and Marquand and Tessreau) and the Big Train Johnson (toiling in excellence alone for the Nats).

But the pair finally met their match back in time with the peerless staff of the 1900’s Cubs, making it to third place overall.  They are followed by the vaunted exploits of the Hall-of-Fame laden Braves, who filled out the list with no fewer than six entries of various pairs, as well as Johnson and Schilling.

Rank	Teammates	Team	Adjusted ERA+ (1)	Adjusted ERA+ (2)	Adjusted ERA+ (Both)	Years
1	Mordecai Brown/Jack Pfiester	CHC	216	195	206	1906/07
2	Mordecai Brown/Ed Ruelbach	CHC	216	184	190	1905/06
3	Clayton Kershaw/Zack Greinke	LAD	187	178	182	2014/15
4	Greg Maddux/Tom Glavine	ATL	211	142	177	1995/96
5	Greg Maddux/John Smoltz	ATL	211	141	176	1995/96
6	Greg Maddux/Tom Glavine	ATL	188	155	171	1997/98
7	Randy Johnson/Curt Schilling	ARI	192	149	170	2001/02
8	Greg Maddux/John Smoltz	ATL	188	141	165	1997/98
9	Greg Maddux/Tom Glavine	ATL	175	144	160	1996/97
10	Greg Maddux/John Smoltz	ATL	175	144	160	1996/97

But though I started with the focus on putting the exploits of Greinke and Kershaw in historical perspective, I came away from the analysis with a newfound appreciation for the unknowns who populated the Greatest Pitching Staff of all time, those Cubbies of the early 1900’s.  History tends to recall those Cubs only in relation to every Cub team since, and the failure of each of them to do what the 1908 (and 1907) Cubs did, and that is to win the World Series.

I’ve mentioned Brown, Reulbach, Pfiester and Lundgren, but you should throw in Jake Weimer, Bob Wicker, Jack Taylor and the supremely alliterative Buttons Briggs and Orval Overall.  Collectively (I might have said “overall” there but decided against it), from 1905-1907 those 9 Cub pitchers combined for an astonishing 17 seasons of 125+ ERA….five or six starting pitchers achieving that lofty mark in each season.  (Plus there were multiple 125+’s in several surrounding seasons, though, curiously, only Brown achieved it in the celebrated year of 1908.)  No other team comes close, including the Braves of nearly a century later, who had 10 in their best three-year stretch. 

But Kershaw and Greinke stand tall in this company, and these seasons will go down in the annals of the game.  They will be teammates for at least the next three seasons, so we can see if they can build on their legacy in progress.