A Pinch of Shame and a Dash of Anxiety

At the end of the last season, many in the Halosphere openly opined that, had the Mariners held their weight against the A's, the Angels may well have won a third straight division title.

As we've learned recently, be careful what you wish for.

I slept late on Saturday night and woke up early on Sunday morning, so by the time 10 AM rolled around, I was thoroughly beat. I watched enough of the first inning of the final game in the Bronx to see Santana give up a run and a three-run jack to Matsui. I was fortunate enough to sleep through most of the rest of the game, but I awoke just in time to see the Halos flail away in futility. The shutout was one of the worst the club has suffered in the past few decades.

Unfortunately that blowout coincided with the (symbolic) end of the first half of the season, as today is the first day of the All-Star Break. It could not have come at a better time. The Angels seems to be able to do nothing right, and those annoying pipsqueaks in Seattle think that their mediocre club is shaping up to be a contender. On Lookout Landing, the Mariner faithful are indulging in more than a bit of hubris, relishing in a nice little run that coincides with a Halo slump. Some are even go so far to discuss what their postseason rotation will look like once they can add the "2007 AL Western Division Champion" pennants to Safeco.

Methinks they jump to conclusions. Yes, it is true that the Mariners are doing quite well at the moment--better than anyone, including their own fans, could have expected. But if there is one constant in baseball, it is the law of regression to the mean. Put simply, a team or individual player that is performing either incredibly well or astoundingly poorly will respectively return to earth or bounce back. Sabermetrics founder Bill James calls this the "plexiglass principle," and in his quest to understand it, he developed the concept of the pythagorean expectation. James found that the ratio of runs scored to runs allowed was a powerful way of predicting a team's winning percentage. Through the beginning of the All-Star Break, the picture in the AL West looks like this (using Baseball Prospectus's Pythagport system):

Team             W    L       RS   RA  W1   L1  Diff
Athletics        44.  43.    377  350 46.8 40.2 -2.8
Angels           53.  34.    435  377 49.7 37.4 +3.3
Mariners         47.  36.    413  404 42.7 40.3 +4.3
Rangers          37.  50.    438  479 40.0 46.9 -3.0

RS stands for runs scored, RA stands for runs allowed, and W1/L1 stand for the team's expected win/loss record given their RS/RA scores. Diff indicates the difference between the actual value and the expected value.

The Pythagport data indicates that the Angels and Mariners have been playing better than expected, the latter more so. It also shows that the A's and Rangers have been underperforming.

What does this mean practically? This explains in some part why the Angels have hit a skid recently--it's nothing more than the universe/God/the baseball deities moving the Halos back towards mean. Hopefully the Mariners also see a bit of slide after the All-Star break. This also means that we can expect the A's to make their typical post-break surge back into contention.

This does not mean that complete faith should be put in the expectation. Teams often end entire seasons with records that differ from their expectations. What could explain this differential? The two accepted stories are luck and bullpens. The latter affects the distribution of runs. Because a game's outcome is binary, one measly run could make the difference between victory and defeat in a single game. The bullpen determines whether or not that run is scored.

How have the bullpens in the AL West fared thus far?

Team ERA
Angels 3.91
Athletics 4.29
Mariners 3.40
Rangers 3.51

For a club that puts so much stock in its bullpen, it is somewhat surprising that the Angels bullpen is the third-worst in the division. It also helps explain why the Mariners have been able to make a run thus far. Their increased offensive production, combined with an effective bullpen means that they can outscore their opponents and then hold onto leads after the starters are pulled. They have managed to accomplish this despite having awful defense and awful starting pitching, which I will discuss on Tuesday.

The Halos, on the other hand, have had their recent run fueled completely by the offense. This is not to say that the club is one-dimensional; Halo starting pitching and defense has remained at least above-average. Once the offense cooled off (a development that was not unexpected with several players, especially Cabrera and Willits, playing at unexpectedly productive levels), the team has reverted to something more along the lines predicted by the pythagorean expectation.

The bottom line is that the Halos should be in fine shape. Their rotation and defense will (hopefully) ensure that the regression to the mean that the team is in the throes of should be short. The Mariners, on the other hand, have no such safety net. Once their offense cools off, their starting and pitching will not be able to pick the up, and a bullpen cannot erase runs allowed by the starter.

Later today, I'll start the first examination of the three contenders in the AL West with our very own Halos.