Dr. Doom provides us with another new metric to measure wins contributed by pitchers. Not wins above replacement, just wins, plain and simple. More after the jump.
Greetings, everyone!
I’m glad you all enjoyed my last series on what I called a new version of Pitcher WAR, but was really just a way of re-framing individualized W-L records. Well, here I am today with yet another new approach.
You probably know by now from my many posts and comments that I adore messing around with baseball numbers and learning more from them. The individualized W-L records I mentioned before are something I’ve been doing for years. At least half a decade, I would guess. But this post is about something I’ve only been horsing around with for a month or so, so enjoy!
Yet again, we’re going to use a pitcher’s ERA+ to figure out a lot about him. This time, though, we’re going to use his actual ERA, as well. When you see a pitcher’s basic stats on Baseball-Reference, you see his ERA and his ERA+. Those are two separate pieces of information. However, they also tell you a third piece of information: a pitcher’s expected ERA. This is obvious. If Bret Saberhagen had a 180 ERA+ in 1989, that tells us that the expected ERA for a league-average pitcher given Bret Saberhagen’s parks would be 80% higher than Saberhagen’s actual ERA of 2.16. In other words, an average pitcher would’ve had an ERA of 1.8 times 2.16, which is 3.89.
Now, we get to even easier math territory. Every nine innings, Saberhagen saved his team 1.73 runs, or .192/inning.
We also know how many innings Saberhagen pitched in 1989: 262⅓. If we multiply the rate of run-saving (.192/inning) by the number of innings (262⅓), we can say that Saberhagen saved a total of 50.368 runs in the course of the year.
OK, that’s all well and good. But we can go another step. And this is where things get interesting, in my opinion. We know that Runs are a bad currency. They’re a bad currency because a run in the 1930 Baker Bowl and a run in 1966 Dodger Stadium are not worth the same thing. That’s why SO many stats use “Wins” instead of “Runs.” Of course, one could convert to wins, that convert back to a run number that would please people more. I’ve often thought that would be a good idea. Alas, no one’s really doing that, and it’s easy enough to do if you really care that much. But for my purposes today, we’ll just use Wins as our currency.
We will recall that we expected an ERA of 3.89. That means that we can take the total number of Runs Saberhagen saved (50.368) and divide by the Expected ERA (3.89) to get a number of Wins: 12.95. Let’s do a little bit of rounding and call it 13 wins. Bret Saberhagen was worth 13 wins in 1989.
Right now (8/23), Chris Sale is cruising to the AL lead in ERA+. His is 220, with Trevor Bauer at 199 and Blake Snell at 196. How do we value these? By this method, Snell remains in third place, with 7.6 wins. Sale and Bauer, though, are closer, with Bauer actuall sneaking into the lead, due to his having pitched 20 more innings than Sale.
This kind of counting stat may be a little more satisfying to some of you all on here. I’m not trying to just inundate you with random thoughts, but I thought you all might be interested. I’ll leave you with some great all-time seasons, and you can see how they stack up to one another (listed with actual W-L, ERA+, and then the assigned W by this formula):
Bob Gibson, 1968 – 22-9, 258; 20.7
Steve Carlton, 1972 – 27-10, 182; 17.3
Dwight Gooden, 1985 – 24-4, 229; 17.3
Sandy Koufax, 1966 – 27-9, 190; 17.0
Roger Clemens, 1997 – 21-7, 222; 16.1
Pedro Martinez, 2000 – 18-6, 291; 15.8
Tom Seaver, 1971 – 20-10, 271; 15.4
Greg Maddux, 1994 – 16-6, 271; 14.2
Randy Johnson, 2002 – 24-5, 195; 14.1
Jake Arrieta, 2015 – 22-6, 215; 13.6
Justin Verlander, 2011 – 24-5, 172; 11.7
Seeing Gibson all those lightyears ahead really gives you a renewed appreciation for that ’68 season, doesn’t it? Gibson had the 3rd-highest ERA+ in the group, as well as the 3rd-highest innings pitched. Yet, the two in combination make his 1968 perhaps the best season in the Liveball Era (and not as far away from many great Deadball seasons as you might think, actually).
Thanks again for bearing with me through another arithmetic-heavy post. Hope you enjoy when I write these once in a while. Anyway, friends, what do you think? I look forward to your comments/criticisms below!
For those interested, a spreadsheet can be downloaded here containing Dr. Doom’s WAR metric (nWAR) from his previous post and his new Wins metric (nWAA) introduced in this post (note that calculations for both are based on FanGraphs ERA+ metric). The spreadsheet contains all 50+ IP seasons since 1961 and includes a pivot table for displaying season-by-season results for any pitcher from that period.