July 25, 2013
Daily Hit List
This is the city, Baseball Prospectus, The Internet. I work here. I carry a spreadsheet. My partner’s Bill Gannon. My name’s Wyers. We were working out of Feature Focus when we got a call about a Daily Hit List.
Let’s look at the navigational options first:
On the left, you have the option to go back and forth among the Hit Lists from different dates. (If you’re at the most recent Hit List, you’ll have only the option to go forward.) On the right, you have the option to send the link to that Hit List via e-mail, Twitter, or Facebook.
Now, to the results of this t… er, I mean of the Hit List:
To the left, you have the team’s rank (more on this in a minute), the team logo (which you can click on to be taken to that team’s audit page), and a list of stats. You have real wins, estimated wins from the Adjusted Standings, the Hit List Factor and Adjusted Hit List Factor, and several stats taken from the playoff odds report, including the odds of winning the division, winning a Wild Card, or making the playoffs by any means, plus one-day and seven-day changes in playoff percentage. You can mouse over any column header to see a pop-up tooltip with more information on the given stat.
The Hit List Factor is an amalgamation of real wins and the three Pythagenpat-based win estimators on the adjusted standings. (Prior to the All-Star Break, we used a version that also incorporated the Depth Chart standings based on PECOTA, to help smooth out early-season instability.) We also have an Adjusted Hit List Factor, which is what’s used to sort the Hit List. It is, admittedly, a controversial adjustment, but it’s informed by real data. The adjustment is based on league quality, and over the past several years, the American League has been dominant over the National League.
What this means is that middle-of-the-pack AL teams will still score higher than some of the top NL teams. This can be hard to stomach (as many fans of top NL teams have told us time and again). But the data doesn’t lie. To illustrate, in interleague play in 2013, the AL has gone .532 to the NL's .468. It's a rather dramatic difference, and one that has persisted over time (you get very similar results looking at 2010 through 2013), so it's not a sampling issue. The AL has consistently been significantly better than the NL in head-to-head competition.
That can overstate the difference between the leagues to some extent (we use somewhat more conservative estimates based on looking at the performance of NL hitters against AL pitchers, and vice versa, converting that to wins through Pythagenpat, and using an offset calculation to create league factors for each), but it’s a dramatic illustration of just how different the leagues are in quality. It’s just that most fans don’t notice because while interleague play is now year round, it’s still a comparatively small part of every team’s schedule.
So that’s it for this week’s Feature Focus. Questions? Suggestions? Other features you’d like, well, focused on? Leave a comment below.