Pythagorean Win/Loss, Luck, and Why the Rays Will Lose the Division

Like most baseball fans this year, I’m captivated by the surge of the Tampa Bay Rays. How can you not be? Coming into this season their highest win total in history was 70 games. They’ve already surpassed that and we haven’t even finished August yet! It’s become pretty evident that Joe Madden’s young team filled with quality starting pitching and exceptional young bats is here to stay.

But will they win the division? Will they make the playoffs? No and yes respectively, and here’s why.

As of this writing (August 20), the Rays are 77-48, 4.5 games ahead of the Red Sox, and appear to be cruising to a division title with a little less than a quarter of the season remaining. Both have comparable remaining schedules - each team’s remaining opponents have the exact same average record of 66-58. So what would lead one to conclude that the Rays are going to choke lose the division lead? A little known statistic to casual baseball fans called Pythagorean Win/Loss.

Coined by Bill James, Pythagorean Win/Loss (also pythW-L) is an estimate of what a teams win/loss record should be based upon the runs they’ve scored and the runs they’ve given up. If a team has a better win/loss record than their pythW-L, they’ve likely been getting “lucky” and are likely to become “less lucky” for the remainder of the season in order for both records to match up accordingly. At the end of a season, Pythagorean Win/Loss is surprisingly accurate (usually within a few games) so in most instances a team winning more games than their pythW-L is likely to incur a losing streak to regress them back to the mean.

Unfortunately the Rays seem to be one of those “lucky” teams. Their pythW-L is 70-55, 7 games worse than their true record (this is often referred to as a luck of +7). The Red Sox, on the other hand, have a pythW-L of 75-51, 2 games better than their record of 73-53 (luck of -2). That 9 game swing would flip the Rays 4.5 game lead around to the Sox, putting them firmly in control. Couple that with untimely injuries to Carl Crawford, Troy Percival, and Evan Longoria, and it seems likely that the Rays magical season could end without a division crown.

The good news? Their pythW-L still puts them 3 games ahead of the Twins for the wild card, so there’s a good chance we’ll see the Rays in the playoffs regardless. And so what may appear to be a collapse in the eyes of many will simply be two very good teams playing exactly as they should be.

Of course, the pythW-L isn’t a perfect predictor of the future and has definitely been wrong from time to time, even over the course of a full 162 game schedule. For instance, last years Diamondbacks finished a whopping 11 games better than their pythW-L. The 2006 Indians were a -12 in the luck category, finishing with a record of 78-84 despite a pythW-L of 90-72. Talk about bad luck!

One thing IS for sure: numbers and predictions are fun, but they’re no replacement for real thing. This stretch run in the AL East should be fun to watch!

 

About the Author

Adam McFarland is the founder and co-owner of TastefullyDriven.com - a contemporary e-commerce site that sells premium home gym equipment, shaving & personal care products, home care products, nutritional supplements, and other products to help improve your everyday life. He also writes for the Tastefully Driven Lifestyle Blog, a blog that covers sports, politics, technology, health & fitness, personal improvement, and more.