What have we learned about the Yankees through the first month of the season?

It’s probably safe to say that the majority of Yankees fans are pleasantly surprised with the team’s current record. Despite the downpour of injuries to key members of the lineup the Yankees enter today with a .630 winning percentage. That pace maintained would equate to about 102 wins by the end of the season and an easy entry into the post-season. For example, the Yankees had the best winning percentage last year with a .586 mark. Everyone knows that you don’t win squat in April, though. Have we learned anything about the Yankees from their first month of action?

The first thing I like to look at when attempting to measure early season success is a team’s strength of schedule. The Oakland Athletics are a good example of why. Their .552 winning percentage sounds very different when considering that six of their wins came against the Houston Astros. How do the Yankees fair relative to their division mates? Here is the American League East division sorted by most difficult schedule, with the actual division standings below:

Right away you can see the problem. With the unbalanced scheduling weighting intra-divisional matchups early in the season, the strength of schedule is just the inverse of the actual standings. This will sort itself out in due time once there have been more inter-divisional series. The one interesting point from this analysis is that all of the AL East teams are in the top half of MLB’s SOS rankings. You can see the complete list here, and if you’re a Mets fan you may want to skip this. Clearly we’re going to have to get more advanced.

The Pythagorean Theorem suggests what we should be seeing in terms of the Yankees' winning percentage. The Third Order Winning Percentage, which uses both underlying statistics, such as runs scored and strength of schedule, gives us something to chew on. On that basis the Yankees are expected to have only a .510 winning percentage. In other words, they’re outperforming their expected winning percentage currently by about three to four games in the win column. The Rays are actually underperforming their estimated win percentage by about the same amount. So by the adjusted standings it would be suggesting a swap with the Yankees in fourth and the Rays in second, while everyone else holds serve. So why are the adjusted standings down on the Yankees?

What stands out the most is the Yankees' record so far in one-run games. They’re a perfect five wins to zero losses so far this season. We just saw last year that a team can ride that wave for far longer than you’d expect, as the Baltimore Orioles made it to the post-season mostly on the back of a 29-9 record in one run games. Clearly there’s some randomness involved in games that just happen to end with only one run separating the two teams, but it’s safe to assume that there is more than just luck involved in such standings. An excellent bullpen has to be a part of success in such a stat, and Baltimore generated the third highest WAR of all bullpens in MLB last year. Does that match up with the Yankees so far this year? Not so much, as the Yankees’ bullpen ranks in ninth place. Coincidentally, that’s exactly the same spot it was for 2012 as a whole.

Could it be that the top tier of the bullpen is performing exceptionally, while the back end is dragging the total numbers down? Unfortunately, it’s not clear that is the answer either. Mariano Rivera is the only Yankee reliever ranking in the top 60 so far in WAR generated from relievers this year. Last year the Yankees actually had finished with two top 30 relievers, and they generated more WAR than Baltimore’s top two relievers. So far it does looks like the Yankees have been a little lucky in generating their perfect record in one-run games and this is probably the reason why adjusted standings don’t view the Yankees as favorable as the current standings.

It’s not all dark and dreary, though, while waiting for the mean regression monster. It’s quite clear that the 2013 version of the Yankees is leaning heavy on its pitching staff for performance. The Yankee pitching staff, as a whole, ranks fourth in MLB in total WAR. The good news is that there are reasons to believe they’ve been pitching better than their results to date. The staff has a 4.00 ERA, but their xFIP points to a 3.60 mark. In this case, Yankee Stadium is not having an impact on the data because neither FIP nor previous seasons’ data suggest the xFIP is an outlier. The staff leads all of MLB in K/BB ratio with a 3.37 reading. Fielding metrics also place the team in the middle of the pack, so it’s not crazy at all to believe that the Yankees’ pitching staff has received some bad luck to date.

Overall, I think it’s safe to say that the Yankees record to start the season has been a blessing. Most fans were probably just hoping for a .500 record at this point. Waiting for the walking wounded to report for duty and lead the team back into playoff contention by the middle of the summer. Instead, the team has been able to keep pace with the pack. They’ve likely received some good fortune when measuring their adjusted standings or when looking at their stellar record in one run ballgames. However, their pitching staff likely has been better than their 4.00 ERA would indicate. So there is reason to be optimistic that regression might not be the dark dreary monster after all. It just depends on your point of view.