This involved all pitchers who pitched at least 1000 innings since 1901, the beginning of the modern era of major league baseball. What I was looking for were indicators of pitchers who were nasty to hit against, be it due to stuff or deceptive motion or a trick pitch, and thus postulated that such pitchers might rank well in stats that measure the following:
- HRs allowed
- Hits allowed
- Runs allows
- Walks - which I included because if a pitcher is always walking men on base and getting into hitters' counts, his nastiness is limited by his inability to command.
I ranked the pitchers by these stats, and that is when I noticed Mariano kept appearing at the top. So for these stats, I averaged each pitcher's ranks in the categories, then ranked these averages. The following table shows the pitchers who ranked in the top 10:
|Pitcher||Hits/9||ERA||HR/9||BB/9||K/9||Avg. of All Ranks||Overall Rank|
If it is not clear, the way to read the table is as follows:
- The 2nd through 5th columns list the pitchers' ranks in particular stats. For example, Mariano ranks 6th in H/9, 10th in ERA, etc.
- The 6th column ranks the pitchers' average ranks. Mariano is 2nd.
Mariano is the only non-dead-ball era pitcher who makes the top 10, and he even outranks most of them. Later on this post will compare Mariano with only pitchers in the live ball era. But first, let's let's discuss the particular stats used and any considerations that provide context.
Note: This exercises uses the stats in the latest version of the Lahman database. I posted a spreadsheet containing stats and rankings for all 1037 pitchers with at least 1000 IP to Google docs - sclick the following link, and download the spreadsheet if you want to sort/filter/edit it: https://docs.google.com/spreadsheet/ccc?key=0AkMu391-e5t0dGNLRmxmc2ZmNHNMY01YVkM0eHU2Zmc#gid=0
The first stat at which I looked was ERA, expecting the leaders to be a bunch of dead-ball era pitchers. This was mostly true, with one exception: Mariano Rivera. Mo's 2.21 ERA ranks him 10th, right behind Christy Mathewson, Cy Young, and Walter Johnson. To put this in context, Mariano is the only pitcher in the top 40 ERA leaders who did not make his debut in the dead-ball era; the next highest-ranking live-ball-era pitcher was Hoyt Wilhelm with a 2.52 ERA. (Mariano's ERA is even more off-the-chart because he pitched in the high-scoring 1990s and 2000s; I didn't expect anyone from this era to rank that high.)
Another stat examined is home runs allowed, expressed as HR/9. Mariano has allowed .47 HR/9, ranking a seemingly pedestrian 264th. However, this is deceiving in that Mariano has pitched in the highest HR environment of all time. This is worth a digression, so the following graph charts HR/9 annually. As you can see, Mariano's career has occurred in the only era that averaged over 1 HR per 9 innings:
To rank Mariano with his peers, I flooked at only pitchers who debuted after 1990 but before 2000. Mariano ranks first in this group, with no one really close to him; the next closest player is his old teammate Bob Wickman at .68, and he is then followed by a group of players such as Pedro Martinez, Derek Lowe, Tim Hudson, and Andy Pettitte. The difference between .48 and .68 may seem small. But what it means is that instead of giving up 65 HRs in his career, he would have given up 91; 26 more home runs in the high-leverage situations in which Mariano pitches would probably have caused an extra Yankee loss or two each season.
Another stat I looked at was WHIP. Mariano's .998 WHIP ranks second all-time. I also measured Hits-per-9 innings (H/9) - Mariano's H/9 ranks 6th.
The final set of stats I examined related to strikeout dominance and control; specifically I looked at K/9, BB/9, and strikeout K/BB. Here is where Mariano ranks:
- K/9: 8.26; ranks 26th all-time. Strikeouts have increase throughout most of baseball history, so pitchers of recent vintage tend to rank highly.
- BB/9: 2.04, ranks 98th all-time.
- K/BB: 4.04, ranks 4th all-time.
- WHIP - H/9 and BB/9 cover hits and walks allowed as separate components; including WHIP would have double-counted those.
- K/BB: K/9 and BB/9 cover strikeouts and walks as separate components, so K/BB would have double-counted those.
|Pitcher||H/9||ERA||HR/9||BB/9||K/9||Avg of All Ranks||Overall Rank|
No one is even close to Mariano. Pedro Martinez's 2nd-place average ranking is 183.6; 108 behind Mariano's average of 75.6. This is a significant difference. You can see that by comparing the difference between Mariano and Martinez to the difference between Martinez and the 20th-place pitcher, Johan Santana, which is only 77.2. (From a statistical perspective, the standard deviation of the "Avg. of All Ranks" values is 163.5, meaning that Mariano is 2/3 of a standard deviation ahead of Pedro.)
While it is not earth-shattering news that Mariano Rivera is unique to the point of freakishness, I was startled to see Mariano ranking with pitchers from an era where the all-time HR leader had 138 HRs.
In closing, I want to make clear that this approach should not be taken for more than it is, which is to examine 'nastiness' using actual stats. Specifically, the results here do not pretend to define the greatest pitchers of all-time. This approach is not applicable to that question for a few reasons; for example, Walter Johnson was a much greater pitcher than Rube Waddell, in that the Big Train pitched twice as many innings as Waddell.
In addition, this approach does not account for era differences. Lefty Grove, for example, pitched in an era when strikeouts were relatively low, H/9 relatively high, ERA relatively high, and so does not get treated well here. This makes a nice segue to upcoming sequels; future posts will adjust these stats by era, and then we will see the implications and where Mariano ranks.