Starting Pitcher Ratings: Top 100 GSDev Seasons

So far in this series, we’ve developed a new method for evaluating starting pitchers and established the scale of the scores produced by that method. Having gone through the intricate methodology, let’s finally get into the actual fun results: the top 100 starting pitching seasons since 1901, according to GSDev.

Rather than going through those seasons sequentially from 100 to 1, let’s do something a bit unorthodox and work our way through pitcher by pitcher, from fewest top-100 seasons to most. To start out, here are the 35 pitchers who had exactly one season in the top 100:

Rank	Pitcher	Year	Starts	Adj GS	GSDev
9	Ron Guidry	1978	37	68.3	19.88
10	Mike Scott	1986	39	68.9	19.86
11	Dwight Gooden	1985	35	69.7	19.50
15	Grover Alexander	1915	44	71.6	19.03
25	John Smoltz	1996	40	67.7	18.28
26	Mike Norris	1980	33	65.0	18.19
29	Kevin Brown	1998	40	66.4	17.77
30	JR Richard	1979	38	63.7	17.72
32	Gerrit Cole	2019	38	67.3	17.67
35	Lefty Gomez	1937	36	68.6	17.46
40	Carl Hubbell	1936	36	69.1	17.34
49	Jake Arrieta	2015	36	65.6	16.99
60	Corey Kluber	2017	31	66.7	16.59
61	Tim Lincecum	2009	32	66.2	16.50
62	Jacob deGrom	2018	32	67.4	16.47
63	Bret Saberhagen	1989	35	65.0	16.47
67	Dolf Luque	1923	37	67.4	16.22
70	Mario Soto	1982	34	63.1	16.18
72	Vida Blue	1971	40	66.2	16.17
73	Smoky Joe Wood	1912	41	70.6	16.13
74	Josh Beckett	2007	34	64.9	16.12
75	Jason Schmidt	2003	30	67.1	16.09
78	Jim Palmer	1975	38	65.0	16.05
82	Robin Roberts	1953	41	63.9	15.98
84	Steve Rogers	1982	35	62.6	15.97
85	John Tudor	1985	41	62.9	15.96
88	Gaylord Perry	1972	40	65.8	15.91
89	Christy Mathewson	1905	40	71.3	15.90
90	Kevin Appier	1993	34	65.6	15.89
91	Don Drysdale	1964	40	64.1	15.89
92	Luis Tiant	1968	32	67.5	15.87
95	Dizzy Dean	1934	36	67.2	15.85
96	Mordecai Brown	1909	34	71.4	15.83
97	Bucky Walters	1939	37	64.9	15.78
100	Nolan Ryan	1977	37	62.9	15.71

A few notes here. As always, remember that the postseason is included; four of the top five seasons listed in this group came from pitchers who had excellent regular seasons and followed them up with extraordinary playoff efforts. (Gooden is the exception; his regular season in ’85 was just THAT good on its own.)

That brings us to the #26 season, Mike Norris’s 1980. If you compare his numbers directly against #29 (Kevin Brown 1998), Norris has both a lower average Game Score and substantially fewer starts. The league average adjusted Game Score in 1998 was higher than in ’80, but only by 0.8; Brown’s average beats Norris’s by 1.4. So what gives?

As I briefly mentioned earlier in the series, 1980 has the lowest five-year rolling regressed average for distance between Game Scores for regulars and Game Scores for scrubs. The surrounding years, particularly ’79 and ’81 but to some extent ’77-’84, are all at least fairly low-deviation in historical terms, whereas 1998 and the surrounding years were pretty normal. You can definitely see that effect in a few entries here (Guidry, Norris, Richard, Soto, Rogers), and let’s just say we’re not done with that effect yet.

Is this adjustment legitimate? We’ve discussed this a bit already, but it strikes me as at least reasonable. The early ‘80s produced relatively few standout pitching seasons compared to the size of the league. From ’79 to ’83 (omitting ’81 due to the strike), the fifth-ranked starting pitcher in bWAR year by year produced 5.8, 5.9, 5.8, and 5.3; from ’69 to ’73 (in a slightly smaller league), the #5 starters by bWAR went 7.8, 6.4, 8.5, 7.1, 7.7. So there may well be an environmental effect present here. I should note that this reduction in deviation does not occur every time the number of standouts drops (GSDev still sees the 1950s as comparatively high-deviation, for instance). But having looked at a couple of general correlations, I’m comfortable keeping the adjustment (with the historical average included in the weighted deviation to keep things from getting too out of hand).

Having established a sense of the performance level required to crack the top 100, let’s move on to the pitchers who did so twice. We’ll sort them by best season, but group the two seasons for each pitcher together:

Rank	Pitcher	Year	Starts	Adj GS	GSDev
5	Steve Carlton	1980	42	65.6	21.25
20	Steve Carlton	1972	41	69.2	18.49
6	Bob Gibson	1968	37	72.6	20.75
33	Bob Gibson	1969	35	69.1	17.61
8	Curt Schilling	2001	41	67.7	19.94
34	Curt Schilling	2002	36	67.0	17.60
17	Dazzy Vance	1924	34	71.8	18.82
55	Dazzy Vance	1928	32	69.8	16.81
24	Hal Newhouser	1946	34	70.1	18.35
46	Hal Newhouser	1945	39	67.2	17.17
38	Ed Walsh	1910	36	74.3	17.40
69	Ed Walsh	1908	49	68.1	16.20
42	Juan Marichal	1966	36	66.2	17.26
54	Juan Marichal	1965	37	65.7	16.82
43	Johan Santana	2004	36	66.2	17.25
77	Johan Santana	2006	35	64.9	16.05
48	Zack Greinke	2009	33	66.6	17.04
76	Zack Greinke	2015	34	65.0	16.07
66	Roy Halladay	2011	34	65.3	16.23
94	Roy Halladay	2010	36	64.0	15.86

If you somehow predicted both “Steve Carlton will have a top-10 season” and “it will not be 1972,” congratulations. This is a pretty surprising result even when accounting for Carlton’s very good four-start postseason in ’80; as you can see, Lefty’s average adjusted Game Score in ’72 is still 3.6 points higher, with the difference in league average accounting for less than half of that (1.4). The rest of the difference is the change in deviation, which was mentioned above; the 1972 weighted average deviation was 9.05 points, somewhat above the historical norm and over 30% higher than 1980's figure.

Aside from Carlton, we add two more members of the top 10. Gibson should surprise nobody; his 1968 is one of the crowning achievements of the art of pitching, even when you account for its very favorable circumstances. Schilling is a bit less predictable, even knowing that the playoffs count. In 2001, regular season Schilling had a 2.98 ERA in 256.2 innings (in a season and a park that both favored hitters); if you add his postseason work, the ERA drops to 2.69, and the innings total balloons to 305. Now consider that Schilling is actually underrated by ERA; he allowed only one unearned run in the entire year. And his FIP stats aren’t exactly lacking; Schilling led the majors with an absurd 7.51 K/BB ratio, and just like his ERA, his FIP improved sharply in the playoffs. Throw in a combined start total (41) that’s unmatched since 1988, and you can start to see what the system is thinking.

The main additional note I’ll throw in here is the startlingly identical seasons posted by Juan Marichal in ’66 and Johan Santana in ’04 – same start total, same (rounded) average Game Score, and the league average and deviation work out so that their GSDev scores area within .01 of each other. You wouldn’t think they were all that similar on the surface (Marichal had 60 extra innings and yet Santana still struck out 50 more hitters), but here we are.

Continuing on, here are the pitchers with three top-100 seasons, presented in the same way as the twofers were:

Rank	Pitcher	Year	Starts	Adj GS	GSDev
1	Pedro Martinez	2000	29	79.1	23.86
2	Pedro Martinez	1999	31	76.2	22.60
14	Pedro Martinez	1997	31	72.2	19.07
4	Sandy Koufax	1965	44	69.5	21.47
21	Sandy Koufax	1966	42	66.0	18.49
27	Sandy Koufax	1963	42	67.7	18.12
16	Lefty Grove	1931	33	72.1	18.83
83	Lefty Grove	1930	34	67.9	15.98
87	Lefty Grove	1936	30	69.3	15.94
23	Bob Feller	1940	37	69.4	18.43
31	Bob Feller	1946	42	66.5	17.67
51	Bob Feller	1939	35	67.0	16.92
44	Tom Seaver	1973	40	66.9	17.22
53	Tom Seaver	1971	35	68.9	16.82
64	Tom Seaver	1977	33	65.1	16.36
57	Justin Verlander	2011	38	64.6	16.68
71	Justin Verlander	2012	37	63.8	16.18
81	Justin Verlander	2019	40	64.3	15.99

See, not every top-100 season features playoff success; Verlander had a rough time in a couple of these Octobers, and Feller, Seaver, and Grove combined for six non-playoff seasons in their nine top-100 entries.

And that’s before we get to Pedro Martinez, who also missed the playoffs in two of the three years presented here, including his #1 all-time 2000 season. Said season has the fewest starts of any entry in the top 35 (and the two years tied for second-fewest starts in that group are Martinez’s other two submissions). It helps when your adjusted Game Score in your best year is nearly as high as Bob Gibson’s UNADJUSTED Game Score in his aforementioned 1968 season.

Fun bonus note: Tom Seaver has a positively Saberhagenesque pattern of excellent odd-numbered years mixed with less-impressive even numbered outings. His three top-100 seasons were all in odd-numbered years, and his fourth-best season (also ranked in the top 150) occurred in 1975.

Only two pitchers had exactly four top-100 seasons. Both were obviously quite dominant, but apart from that, they’re remarkably different:

Rank	Pitcher	Year	Starts	Adj GS	GSDev
22	Walter Johnson	1913	36	74.9	18.48
37	Walter Johnson	1912	37	74.0	17.40
65	Walter Johnson	1915	39	69.3	16.32
86	Walter Johnson	1918	29	73.4	15.95
36	Clayton Kershaw	2015	35	66.6	17.45
50	Clayton Kershaw	2013	37	64.5	16.96
79	Clayton Kershaw	2014	29	67.4	16.03
80	Clayton Kershaw	2016	25	68.4	15.99

Speaking of pitchers who lacked postseason success… Kershaw appeared in the playoffs in all four of these years; his results weren’t necessarily as bad as his reputation would suggest, but they also didn’t live up to his regular season standard. Johnson, meanwhile, spent his entire career on the perennially lousy Senators, and thus didn’t make a World Series until his top-100 days were behind him.

In Johnson’s case, four top-100 seasons might feel low for a pitcher often referred to as the greatest ever. If it helps, the Big Train had four additional seasons ranked between 101 and 125.

Another note: Kershaw’s 2016 included four postseason starts, meaning he made only 21 in the regular season. He didn’t qualify for the ERA title that year, but if he had, his 1.69 ERA and 1.80 FIP would have both been career bests, and that’s saying quite a lot in Kershaw’s case.

Kershaw and Johnson get our total up to 81 out of the top 100 seasons. I’ll present the last three pitchers consecutively and with minimal comment. That’s not because I don’t have anything to say about them; it’s because the natural next step after ranking the best individual seasons is ranking the best overall careers, and each of these pitchers will feature prominently on that list.

Greg Maddux

Rank	Year	Starts	Adj GS	GSDev
13	1995	33	71.9	19.39
39	1994	25	73.5	17.35
52	1997	36	66.8	16.88
68	1998	36	65.5	16.21
98	1992	35	64.8	15.76
99	1996	40	64.1	15.75

Maddux’s ’94 and ’95 rank that high despite the strike; ’94 ties Kershaw’s 2016 for the fewest starts of any top-100 season, and his GSDev in the shortened campaign outpaces Clayton’s effort by a substantial margin. Like Kershaw, Maddux wasn’t quite as good in the playoffs as he was in the regular season, but in the Octobers on this list (1995-98), he posted the following numbers: 15 starts, 109 innings, 2.13 ERA, 3.06 FIP. (The ERA is a bit deceptive as he also allowed 14 unearned runs, but that’s still a very solid RA of 3.30. Not quite the 2.47 RA he had in the accompanying regular seasons, but not too shabby against postseason opposition either.)

Randy Johnson

Rank	Year	Starts	Adj GS	GSDev
3	2001	39	71.3	22.14
12	1999	36	69.2	19.46
18	1995	33	70.7	18.57
19	2004	35	68.5	18.56
28	2000	35	67.1	17.80
41	2002	36	66.6	17.33

That’s not just six top-100 seasons; all of them made the top half of the list. And when a pitcher capable of running off half a dozen top-50 entries gives you his best regular season, then caps it off with a legendary postseason run? Well, you get the third-best pitching season of the stretch from 1999-2001 (which GSDev also considers the third-best season ever, period).

Roger Clemens

Rank	Year	Starts	Adj GS	GSDev
7	1997	34	72.9	20.41
45	1986	38	65.6	17.19
47	1987	36	65.3	17.11
56	1998	33	67.4	16.74
58	1991	35	66.3	16.67
59	1988	36	65.6	16.65
93	1990	33	65.5	15.87

Clemens’s first top-100 season came in 1986; his last came in 1998. That 12-year gap is easily the largest of any pitcher who had multiple seasons on this list, and Clemens posted five more top-100 seasons in between. And for all the time we’ve spent on the playoffs in this post, Clemens only had double-digit postseason innings in one of these seven years. There’s a reason he won seven Cy Young awards.

A final note before wrapping up: You may notice the timeframes of the selections here are a bit different than might be expected in a list of the greatest pitching seasons. For the sake of comparison, here are the top 100 seasons by bWAR and GSDev (limiting bWAR to 1901-2022 to put the comparison on even terms) broken down by decade:

Decade	bWAR	GSDev
1901-09	18	3
1910-19	22	7
1920-29	6	3
1930-39	9	8
1940-49	7	4
1950-59	1	1
1960-69	7	9
1970-79	12	10
1980-89	5	11
1990-99	7	17
2000-09	4	13
2010-19	2	14

That is a noteworthy difference, to put it mildly. The shift is one that makes sense to me intuitively, as the league is nearly twice as big now as it was in 1901, and also draws from a much wider base of potential players (racially and geographically) than it did a century ago. (When sorting by year, the median top-100 season by bWAR was in 1936; for GSDev, it’s in 1985. The median MLB team season between 1901-2022 was in 1976, significantly closer to the GSDev median.) The interesting thing about that result, however, is that GSDev does not explicitly adjust for the size of the league, or the quality of the competition, or any of the other timelining considerations that are often made in all-time ratings (I added some of them to Weighted WAR, for instance). I have some theories as to where this result comes from, and I’ll try to explore them as the series moves forward.

But first, having gone through the list of the greatest seasons, the follow-up question practically asks itself: Which pitchers had the best careers? Next time, we’ll start to explore how that question might be approached by GSDev.