There are a lot of baseball "people" who believe that Sandy Koufax—while not necessarily the greatest pitcher career-wise of all-time—may have been the greatest left-handed pitcher who ever lived. Nobody will ever know for certain if that is true because it’s not a provable notion. However, my opinion recently changed a bit after I looked into the matter more closely. The spark that got me going on this was my curiosity as to how Johan Santana stands up to the greatest lefties in history. This was a few weeks before his 17 K effort against the Rangers but that sort of performance only reiterates why I wanted to look a bit further into the validity of the “Koufax greatest lefty ever”-thing.
There is no question in my mind that Santana is a brilliant and dominating pitcher. So, Koufax would have to be uber-brilliant to truly be "heads and tails" better than everyone else including Santana. If Koufax was truly as good as many people believe, then he should dominate Santana in a career-comparison. Koufax’s career is mainly remembered for six seasons from 1961-1966 in which he was the best pitcher in baseball. Santana has been a starting pitcher for most of six seasons. So, I figured I'd compare Koufax’s six-season run to Santana’s six-year stint as a starter. The best and easiest tools to compare pitchers from different eras are; ERA+, Winning %, Wins, and Cy Young awards. While ERA+ (some may argue that WHIP is better but it’s difficult to compare WHIP without respect to the league average) is probably the best measure, none of the statistics are the "end-all" for evaluating pitchers. Near the end of the post I delve deeper into the pitfalls of using ERA+ to compare different eras.
The results of the comparison between Koufax and Santana were--not-surprisingly--close. While there is no disputing Koufax’s brilliance, there is also no disputing the fact that Santana’s numbers are almost equal. Koufax holds an advantage in every category but it is by a razor-thin margin and sometimes not an advantage at all. Here is a more in-depth comparison of each statistic:
Koufax has the edge but the difference here is virtually negligible. In fact, I am guessing that if ERA+ was only calculated using starters' ERA, Santana may have the edge in this category.
Both percentages are astronomical. Koufax again has a slight edge.
Koufax appears to have the edge here but WHIP is not weighed for league average like ERA +. There is no question that Santana is pitching in an era with significantly more offensive production. There is no doubt in my mind that Santana holds the edge in this category based on league averages.
Cy Young Awards
Santana should have won the 2005 AL Cy Young Award. He had more innings and strikeouts than Bartolo Colon and a much better ERA and WHIP. In fact, I’m not sure how any baseball person could have voted Colon over Santana. The numbers weren’t even close. Santana should finish in the top three of the Cy Young voting this year which would give him four top-three finishes in four seasons. Koufax accomplished the same feat.
These numbers are so close that if Santana puts together a phenomenal ’08 campaign, then a comparison of Santana and Koufax might end up in a wash if it isn't already. After piling up all of this info, I had two choices: 1). I could conclude that Santana—being that close to Koufax—is just that close to being the greatest lefty of all-time (or at the very least having the greatest six-year run of all-time), or 2). I could research this a bit further. There is no doubt that Santana is great. But, if he really is the greatest "peak" lefty of all-time—or at least right near the top of the list—then people would be making a bigger deal about him than they are. I just have to think that there have been pitchers that were quite a bit better than Santana—and thus quite a bit better than Koufax.
Since Koufax’s reputation is solely predicated on his six-year run of brilliance, it would stand to reason that his six-year run would have to be considerably better than every other pitcher in baseball history in order for the moniker of “greatest lefty pitcher of all-time” to hold true. If a pitcher had a similar six-year run and combined that with 10 more years of solid pitching then that pitcher would get the edge overall for being equal in brilliance but doing it over a much longer period of time. Since Santana put up such a good fight in a “peak” comparison to Koufax, it became obvious to me that there had to be other pitchers out there who have put up Koufax’s numbers while doing it for a much longer period of time.
So, I decided to do a comparison of Koufax to the greatest left-handed pitchers of all-time in terms of best six-year runs. Since Koufax’s entire reputation is based on that time-frame, then he should have the greatest run of the bunch. There have been many “good” left-handers but there have only been a few “great” ones. For the comparison, I chose Lefty Grove, Warren Spahn, and Randy Johnson along with Koufax and Santana.
Below are the best six-year stretches that I could find for each player:
Here is how those five pitchers compare:
Johnson (‘97-‘02) 74.10% (120-42)
Grove (‘26-‘31) 73.50% (136-49)
Koufax (‘61-66) 73.30% (129-47)
Santana (‘02-‘07) 70.50% (86-36)
Spahn (‘53-‘58) 65.30% (124-66)
Johnson (‘97-‘02) 177
Grove (‘26-‘31) 169
Koufax (‘61-66) 162
Santana (‘02-‘07) 159
Spahn (‘53-‘58) 132
Cy Young Awards
Johnson (‘97-‘02) 4
Grove (‘26-‘31) N/A
Koufax (‘61-66) 3
Santana (‘02-‘07) 2
Spahn (‘53-‘58) 1
Koufax (‘61-66) .97
Santana (‘02-‘07) 1.01
Johnson (‘97-‘02) 1.07
Spahn (‘53-‘58) 1.16
Grove (‘26-‘31) 1.19
Johnson (‘97-‘02) 12.33
Santana (‘02-‘07) 9.83
Koufax (‘61-66) 9.44
Grove (‘26-‘31) 6.08
Spahn (‘53-‘58) 4.3
There isn’t much in the name of conclusive evidence to be found here—and there really never is when doing any sort of player comparison from different eras. However, these comparisons leave me with a few "new" thoughts. First, I don’t think there is any way that Koufax can be considered the greatest left-handed pitcher of all-time by any measure even if we base it entirely on his “prime.” Randy Johnson’s ERA+ over his six-year peak (177) is much better than Koufax’s (162). Johnson’s winning percentage was better and he won more Cy Young Awards. Johnson also had one of the greatest seasons in MLB history to not result in a Cy Young Award. In 1997, he went 20-4 with a 198 ERA+. In fact, that was the best season of his career. So, not only did he win four Cy Young Awards in that six-year stretch, but he also had the greatest year of his career that ironically didn’t result in a Cy Young Award. A Grove/Koufax comparison is much closer although Grove has the edge in both winning percentage and ERA+ so his six-year stretch is at the very least equal to Koufax. While there is no question that Koufax was brilliant, I cannot accept that—even for a brief period of time—he was the best left-handed pitcher in baseball history.
If not Koufax, then who?
In my list of the 50 greatest MLB players of All-Time, I rated Lefty Grove as the best lefty of all-time just ahead of Randy Johnson. I’m starting to think that Johnson has a legitimate claim to the title. First, Randy Johnson’s career Batting Average Against (BAA) is .218. Grove’s is .255. That is a huge difference. Then, consider Johnson’s enormous advantage in K/9 of 10.78 to 5.18. That means Johnson prevented six more players per nine innings from even putting the ball in play. Grove does hold a 148 to 137 edge in ERA+ but using that tool to compare players from vastly different eras can be precarious. ERA+ is a helpful tool but it becomes ambiguous when the league as a whole is mediocre. Grove played in an era with few great pitchers. Johnson played in an era with many great pitchers. There isn’t a pitcher from Grove’s era—other than Grove—with an ERA+ above 130 (min. 1,500 innings pitched). There are six pitchers in Johnson’s era with an ERA+ above 130. The likely result of that scenario would be a higher ERA+ for Grove because his league was littered with poor pitchers and virtually no elite pitchers.
Another factor that would skew Grove’s ERA+--or I should say devalue Johnson’s—is the prevalence of relief “specialists” and “closers” in modern-day baseball. Those pitchers often have the best ERA's in the league and those numbers are factored into ERA+. In fact, relievers collectively have a better ERA than starters in modern-day baseball. I am fairly certain that was not the case in Grove’s era. Relievers are also pitching more innings than ever before which means their lower ERAs are going to have an even bigger impact on the league average hurting modern-day pitchers in the ERA+ category. If Johnson and Grove were compared in ERA+ only using the league average for starters, Johnson may, in fact, have Grove beat in the ERA+ comparison. I am guessing it would be a negligible difference at the very least. Instead, relievers are thrown into the ERA+ making Grove look like the clear winner in that comparison.
Also—and I missed this entirely when I made my Top 50-list—Grove pitched a number of innings in relief over his career. That can significantly slant statistics towards looking better than they should. John Smoltz and Dennis Eckersley are the best examples of this. “Eck” was a run-of-the-mill pitcher as a starter. It wasn’t until he was able to pitch one or two innings at a time that his statistics blew up. Smoltz was always a good pitcher but his statistics also blew up when given the chance to pitch one or two innings at a time. As a result, “Eck” and Smoltz have slightly misleading ERAs at least when compared to other starters. Grove had that same advantage. Johnson has not.
I don’t think it’s clear-cut in either direction. Johnson pitched in the most difficult era of all-time and the era with four of the best pitchers in MLB history. Grove pitched in a difficult era in his own right but likely saw his ERA+ benefit from a league-wide pitching drought. Johnson’s BAA, K/9, and WHIP advantage end up being the deciding factor for me. I believe that Johnson is the greatest lefty of all-time. I won’t argue with anyone who thinks Grove should be given that title. One thing I do think is clear is that Johnson and Grove are clearly the two best lefties in MLB history. Koufax—albeit very good—probably gets overrated at least in the discussion of “greatest lefty of all-time”. Johan Santana is well on his way to cementing his status as one of the five greatest lefties in baseball history.