Have the A's been the victims of a tough schedule?

Disclaimer: This is a long post, with a lot of text, and some charts that require interpretation. It also has ambiguous conclusions, because of some hard-to-account for errors. There's a solid chance you will feel this is a waste of your time. I do believe it can provoke good conversation, and I also want to post this anyway, since I did it. Please do skip this if you don't want to think about it. Thanks.

The A's have played some good teams, including Toronto, Tampa Bay, Boston, New York, Texas, and the Angels. These teams may represent a stronger early schedule than typical for the AL. On top of that, with injuries, call ups, and random luck, each player on the A's has faced an extremely varying set of opposing batters and pitchers. For example, Anderson has pitched against tougher lineups than Cahill.

When we evaluate the performance of the A's personnel, we don't correct for "strength of schedule". For example, we look at Braden's .743 Allowed OPS, and think "Ok, above average". The AL average OPS is .766 in 2009. What we don't account for is the fact that the batters Braden has faced are actually averaging a .792 OPS so far in 2009, making Braden's pitching exceptionally good.

In this diary fanpost, I'm going to use Baseball Prospectus' data on the Average OPS of batters faced for our pitchers, and compare it to the OPS our pitchers have actually allowed. This will allow us to correct for the possibility that the A's have faced tougher lineups, and for the possibility that some A's have faced particularly tough tasks. I'll also do a similar analysis on the quality of pitching our hitters have faced.

The conclusions of the analysis (here ahead of time for clarity) are:

1. The A's have faced tougher than average (or hotter than average) lineups, and better than average opposing pitching.

2. Some A's pitchers performances thus far, such as Bailey, Braden, and Anderson are better than they appear, since they faced tougher opponents.

3. Cahill and Wuertz have faced below-average opposition, and thus are  worse thus far than they appear.

4. Powell, Holliday, Ellis, and most of the A's lineup have faced exceptionally tough pitchers, making them look worse than they are.

5. Nomar was not as good as he appeared, as he faced weak opposing pitching.

Finally, these conclusions are seriously dependent on a few key assumptions. A list of these assumptions, and defenses of them, are in Comment #1  (in order to avoid bogging down here). I expect that AN will find many more flaws in this work than I cover in comment #1. On to the real analysis...

EVALUATING THE A's PITCHERS

So the first step in adjusting performance is to look at the how good the opposing batters each pitcher has faced have been in 2009. Below is a chart of the average OPS put up by opposing batters in 2009.

What this chart shows is that Trevor Cahill has faced below average batters in 2009. The players Cahill has pitched to have averaged a .75 OPS, whereas a league average OPS is .766. In contrast, most of the A's pitchers have faced extraordinarily good hitters/lineups. The biggest example is Andrew Bailey, whose opposing batters are putting up a .797 OPS, the equivalent of facing 2009 Ichiro in every single at bat.

Next, I take the OPS that the A's pitchers have actually allowed, and compare it to the league average OPS, as well as the OPS of the batters they faced. For Bailey, this meant calculating two values:

Differential relative to league average = .766 (league average) -.417 (OPS allowed thus far in 2009)  = .349

Differential relative to opposing batters' normal OPS = .797 (OPS of Bailey's opponents in 2009) - .417 = .38

Thus, Bailey appears to have allowed an OPS .349 lower than the OPS an average pitcher would allow. BUT, given how good the batters he faced were, he actually saved .380 points of OPS.

A chart with the OPS differentials for each A's pitcher is below:

So what this chart shows is that Bailey, Casilla, Outman, Ziegler, and Braden have not only done better than average (blue bar = positive), but also done so against really tough lineups (red bar = bigger than blue bar).  Wuertz has done above average, but not as far above average as one would think, since he faced easier than average lineups. Similar analysis for the below average pitchers. For example, Cahill appears to be .13 OPS points worse than average, but in fact was even worse, since he had a slightly easier than average set of opponents.

ANALYSIS OF THE A's LINEUP:

The cumulative 2009 OPS allowed by opposing pitchers for each A's hitter is shown in the chart below.

This shows that Powell has faced some really stingy pitchers, who are allowing only a .670 OPS thus far in 2009. In contrast, Nomar faced some relatively easy pitchers, who allowed a .781 OPS.

Next, we calculate the differentials, which show how the hitter compares relative to league average (blue), and relative to the OPS that the pitchers they face normally give up. (red). This is similar to the analysis for pitching above.

So Chavez has been atrocious, no matter how you put it :( . Holliday, Cust, Suzuki, and Kennedy have been above average. Holliday appears only average, but given he faced tougher pitchers, doing average (.766OPS) was a victory. His opposition usually gave up just a .710 OPS.

So, to conclude. The A's have faced tough competition. They have also been WAY below average in the lineup and the SP rotation. However, they are less below average than they appear, since they've faced a tough schedule. Thanks a lot if you've made it this far. I'm just trying to help AN waste even more of your time :)