It’s interesting to note that both Johan Santana and Sandy Koufax pitched in 12 major league seasons. For Koufax, his career spanned 1955 through 1966. For Santana, he pitched in the big leagues from 2000 until 2012. He missed all of 2011 which is why he pitched 12 seasons. Let’s just put some of the numbers out there between the two and see how they line up.
Santana had a stretch of five seasons during which he did not pitch less than 219 innings. During Koufax’s career, he had a stretch where he threw over 300 innings in four out of six seasons. The times were different, of course, as Bert Blyleven informs us, frequently. Santana had 15 complete games during his career. Koufax went the distance 15 or more times in five seasons. That’s why Koufax had more wins and more losses. He rarely had to rely on his bullpen finishing what he started.
Their WHIPs are pretty much identical. Koufax gave up fewer hits, but Santana had much better control. They both struck out about a batter an inning.
It’s interesting to note that while Koufax gave up nearly a half run less per nine innings over his career, Santana’s ERA+ is actually 5% better than Koufax’s. Why? In the late 1950s, offense was down. In 1961, baseball raised the mound in an attempt to help hitters. It worked, and yet run scoring was still not high. Santana was pitching during an era when offense was prevalent, for whatever reasons you want to credit.
Looking at the totality of their careers, one would have to say that they are very much equivalent, particularly when adjusting for era. Koufax was very much an average big league pitcher over his first six seasons, and then he became one of the best pitchers ever over a six year stretch to close out his career. Santana had two years of adjusting to the big leagues after being forced to be in the big leagues because of the Rule 5 status. His second year also wasn’t great. However, from 2002 through 2010, he never had an ERA+ under 129 (29% better than average). Santana’s stretch of success was a couple of years longer than Koufax’s. Unfortunately, once Santana got hurt in 2011, his career was basically over. He tried multiple comebacks but was not successful.
Both great left-handers had careers that ended far too soon. Koufax made that decision as a 30-year-old. Santana’s great stretch ended as a 31-year-old. Koufax benefited - in terms of long-term status - because he didn’t end his career with injury. He quit too early, rather than too late. Santana, for many, may have hurt his stock by pitching hurt and trying to come back for so long.
One of those things that people like to look at is a player’s peak. How good was a player, or a pitcher, when he was at his best. As it relates to the Hall of Fame, the minimum peak seems to be five or six years.
While I noted above that Koufax's peak was a six-year period, Santana's was an eight-year period. But to be equal, I just looked at Santana's best six-year stretch.
As you recall from the 12-year comparison, Koufax has a better ERA during his peak years than Santana did. In this case, Koufax also was better relative to the league. He was 56% better than league average while Santana was still very impressive at 50% better than the league. They both gave up right around one base runner per inning. Koufax's control was significantly better during the great half of his career, with a walk rate of nearly one less per nine innings.
They both recorded a lot of strikeouts. While hitters a decade ago didn't strike out quite as much as they do now, they struck out a lot more than they did in the '60s. In other words, 9.4 K/9 in the '60s is more impressive than 9.4 K/9 in the '00s because fifty years ago, batters took a lot of pride in not striking out.
Sandy Koufax - Led the league in strikeouts four times. Led in innings pitched twice. Led in ERA five times and ERA+ twice. He led the league in WHIP four times. He led the league in K/9 six times. He won three Cy Young awards and finished in the top three four times.
Johan Santana - Led the league in strikeouts three times. He led in innings pitched twice. He led the league in ERA and ERA+ three times. He also led the league in WHIP three times. He led the league in K/9 three times. He won two Cy Young Awards and finished in the top three four times.
While this is a very quick analysis and comparison of the two pitchers, I think the high-level data does show that Sandy Koufax was a little better statistically in his era during his peak than Santana was. Looking at their full careers, the argument could certainly be made that Santana had the better career.
Wins Above Replacement - bWAR, Koufax led 53.1 to 50.7. Koufax has a bigger advantage in fWAR (54.5 to 45.3). And again, 46.5 of Koufax's fWAR was in those six peak years.
So yes, Sandy Koufax was the better of the two pitchers. But it does seem that even us, Twins fans, may not realize how great Johan Santana was. I watched him pitch. I knew he was good, but to look at the numbers, and realize just how similar Santana's career was to Koufax's, it surprised me.
Obviously Johan Santana will be a member of the Twins Hall of Fame, likely the first time he appears on the ballot. But maybe the Twins fan base should also start pushing the candidacy of Johan Santana for the Hall of Fame in Cooperstown too.