I've been looking around the web for measures of MLB strength of schedule and have found three results so far. One, Andy Dolphin's site, hasn't started updating for 2009. A second, ESPN.com, doesn't make their methodology obvious at all. The third, BPro, also doesn't explain its methodology, but at least it's easy to figure out how to use the adjustments.
By comparing BPro's second- and third-order wins, you can determine how much credit they're giving to each team for strength of schedule in third-order wins. As a reminder, third-order wins are based on adjusting equivalent runs for SoS and then using Pythag (-pat or -port I'm not sure). Not perfect, but pretty good. Here's each team sorted with the most difficult schedules at the top. Again, because the methodology is a black box, mentally apply large error bars and some skepticism.
| Team | Bpro SoS |
| Indians | 1.8 |
| Orioles | 1.4 |
| Athletics | 1.0 |
| Giants | 0.9 |
| Red Sox | 0.9 |
| Marlins | 0.9 |
| White Sox | 0.7 |
| Padres | 0.7 |
| Astros | 0.5 |
| Nationals | 0.3 |
| Rockies | 0.3 |
| Twins | 0.3 |
| Yankees | 0.1 |
| Angels | 0.0 |
| Pirates | -0.1 |
| Royals | -0.2 |
| Brewers | -0.2 |
| Phillies | -0.2 |
| Mariners | -0.3 |
| Tigers | -0.3 |
| Braves | -0.4 |
| Cubs | -0.4 |
| Diamondbacks | -0.5 |
| Cardinals | -0.5 |
| Reds | -0.6 |
| Mets | -0.7 |
| Blue Jays | -0.9 |
| Rays | -1.4 |
| Dodgers | -1.5 |
| Rangers | -1.5 |
As a recent FanShot mentioned, the Indians won't play another AL East team until mid-August and have only four more games left against non-Orioles AL East teams.
To have something to compare BPro's numbers to, I attempted to turn ESPN's strength of schedule data into something meaningful. By pro-rating BPro's numbers to 162 games, I could create an opponents' winning percentagem which is the format of ESPN's numbers (I think). ESPN's distribution of winning percentages were about half as wide as BPro's, so I doubled them to make a comparison more meaningful. The table below is initially sorted with which teams' schedules ESPN thinks were harder as compared to BPro at the top, but you can click on the column headers to re-sort by the ESPN SoS adjustments themselves, too.
| Team | Bpro SoS | ESPN SoS | Diff |
| Dodgers | -1.5 | 0.0 | 1.5 |
| Cubs | -0.4 | 0.8 | 1.2 |
| Brewers | -0.2 | 0.8 | 1.0 |
| Blue_Jays | -0.9 | -0.1 | 0.8 |
| Angels | 0.0 | 0.8 | 0.8 |
| Rangers | -1.5 | -0.8 | 0.7 |
| Padres | 0.7 | 1.3 | 0.6 |
| Mets | -0.7 | -0.1 | 0.6 |
| Astros | 0.5 | 1.1 | 0.6 |
| Reds | -0.6 | -0.1 | 0.5 |
| Tigers | -0.3 | 0.2 | 0.5 |
| Yankees | 0.1 | 0.6 | 0.5 |
| Twins | 0.3 | 0.7 | 0.4 |
| Rockies | 0.3 | 0.7 | 0.4 |
| Cardinals | -0.5 | -0.3 | 0.2 |
| Royals | -0.2 | -0.1 | 0.1 |
| Rays | -1.4 | -1.3 | 0.1 |
| Diamondbacks | -0.5 | -0.5 | 0.0 |
| Mariners | -0.3 | -0.4 | -0.1 |
| Giants | 0.9 | 0.8 | -0.1 |
| Orioles | 1.4 | 1.1 | -0.3 |
| Pirates | -0.1 | -0.6 | -0.5 |
| Indians | 1.8 | 1.2 | -0.6 |
| White_Sox | 0.7 | -0.2 | -0.9 |
| Athletics | 1.0 | 0.0 | -1.0 |
| Red_Sox | 0.9 | -0.3 | -1.2 |
| Phillies | -0.2 | -1.5 | -1.3 |
| Braves | -0.4 | -2.0 | -1.6 |
| Marlins | 0.9 | -0.8 | -1.7 |
| Nationals | 0.3 | -1.4 | -1.7 |
One thing I notice about the ESPN numbers relative to the BPro numbers is that ESPN doesn't favor the bad teams or knock down the good teams as much as BPro does. Perhaps that suggests ESPN better accounts for the fact that bad teams make their opponents look better and good teams make their opponenets look worse.
As for what the two systems agree on:
- The Rays and Rangers have had two of the easiest schedules in the majors.
- The Indians and Orioles have had two of the hardest schedules in the majors.
One thing I think is missed here (although maybe not) is the number of home and away games played by each team. At one point, the Rockies had played only 20 home games while another team had played 30. That certainly falls under strength of schedule, even though it's not strength of opponents.
Anything else we can take away from these black box systems? Any ideas for creating our own SoS adjustments?