Steve Webb
LOS ANGELES — You know the feeling, Dodger fans. I’ve felt it, too. That gnawing feeling you’ve had in the pit of your stomach all year. The feeling that, even though the Dodgers are going to finish somewhere north of 100 wins, somehow they should be doing better than they are. And then, you look to the north, at those pesky Giants, who still sit in first place, and you feel something similar. That these guys really don’t deserve all the breaks that they’ve been getting this year. Well, I’m here to tell you, dear fans, that you are not wrong. And there is science to back up both of these opinions. It all comes down to one obscure, but important statistic: Pythagorean winning percentage.
Good ol’ Pythagoras
Everybody remembers Pythagoras from Geometry class. He was the dude that figured out how you could reliably gauge the length of the hypotenuse (the long side) of a right triangle if you knew the length of the other two sides. He even came up with a nifty formula for it, the famous Pythagorean theorem: a2 + b2 = c2. So, for example, if you had a triangle that had two sides of three inches and four inches, you just knew that the long side of the triangle would be five inches because math. And we all had hours of fun figuring out triangles back in the day.
Enter Bill James
So what does all this have to do with baseball? Well, that’s where famous baseball wonk Bill James comes in. Probably the first-ever baseball “blogger”, James cranked out a newsletter back in the 1970s called the Baseball Prospectus, in which he crunched the numbers for all sorts of baseball stuff, and in so doing slowly but surely revolutionized the game. It is because of Bill James that nerds like Andrew Friedman and Farhan Zaidi are running baseball teams these days, and not some crusty old retired ballplayer.
Anyway, James developed a formula back in the day to figure out how you could accurately measure how a team was doing, regardless of lucky bounces and bad breaks. Using the data compiled over thousands of different baseball seasons for every big league team to ever exist, James came up with what he called the Pythagorean Winning Percentage. It was a measure of how a team should be doing in the standings, not necessarily of how it actually is doing. But given the many years and many teams, the formula eventually is proven to be an accurate measure of the strength of a team.
It all comes down to runs
James started with a simple premise: that the purpose of baseball is to score more runs than the other team. Not to get more hits, not to get more strikeouts, not to get more leaping catches. To get more runs. So, James figured that one could reliably predict how well a team would be doing over the course of the season if he knew only two numbers: total runs scored and total runs allowed. Then taking those two numbers, he came up with a formula that could pretty accurately predict a team’s wins for the season. He called it the Pythagorean Winning Percentage because of the resemblance to Mr. Pythagorus’s famous triangle theorem. It looks like this:
Later stat geeks changed the co-efficient a bit, but the idea remained the same. If I know your runs scored and allowed, I can pretty accurately predict how many wins you should have. The best example this season is the Cincinnati Reds, with their run differential of 43 runs. Their expected record is 83-74, and their actual record is 82-75. Pretty darn close. Well played, stat nerds!
So what about the Dodgers?
So here’s where we get to the nub of things. The 2021 Los Angeles Dodgers. With six games to go, the Dodgers have scored 783 runs, and with their strong pitching have surrendered only 536 runs so far this year. This figures to a run differential of 247 runs, by far the best in baseball. The next closest this season are the hated Astros* with a run differential of 205 runs. For comparison, the run differential for the first place Giants is only 197 runs. Still good, but about 20 percent less than the Dodgers.
Expected Wins for LA & San Francisco
So, if we put both these numbers through Mr. James’s magic formula, what do we find? That, with their run differential, the Dodgers should have 104 wins right now, instead of the 100 that they actually have. And the Giants? Their expected record right now should be right around 98 wins, instead of the 102 that they actually have. So instead of staring a Wild Card game in the face, the Dodgers should be sitting on a six game lead in the NL West right now, about to wrap up their ninth consecutive NL West crown.
But they’re not. So, that feeling you’ve had all season is right. The Dodgers are winning fewer games than this team should be winning, and the Giants are getting a lot of good bounces up in Oracle Park and overperforming their expectations.
So if from your couch this weekend, you yell at your TV and say something like, “These damn Giants have no business being in first place ahead of the Dodgers!”, you’re right. That’s just science.
