How the West Was Won?

Dan puts the West under the microscope.

This past offseason, I made a few predictions about what the 2002 season would bring, some of which turned out to be—well, less than accurate.  Of course, I haven’t given up hope on all of them; it’s still possible, for example, for Jeff Bagwell to finish the season with 67 home runs.  However, there’s no question that when I said, “I don’t see the 2002 AL West being much of a race,” I was dead wrong.  Not only has the race been one of the best in a long time; it’s involved three teams—the Seattle Mariners, the Anaheim Angels, and the Oakland Athletics—whose performance changed quite a bit over the course of the season.  Those changes shaped the race.  But what caused them?

To answer that, let’s compare each team’s performance before and after the All-Star break (through September 13).  While the teams didn’t experience these turnarounds right at the All-Star break, it provides a convenient reference point common to all three teams.  Here is what each team did before the All-Star break:

Pre All-Star
Team     Record      R/G    RA/G
SEA   55-33 (.625)  5.23    3.91
ANA   51-35 (.593)  5.30    4.28
OAK   50-38 (.568)  4.77    4.49

And from the All-Star break through September 13:

Post All-Star
Team     Record      R/G    RA/G   WPct Chng  R/G Chng  RA/G Chng
SEA   29-30 (.492)  4.88    4.76      -21.4%     -6.6%      21.8% 
ANA   41-20 (.672)  5.15    3.47       13.3%     -2.9%     -18.8%
OAK   42-17 (.712)  5.22    3.41       25.3%      9.4%     -24.1%

Two things are clear from the above charts: First, Anaheim has been the most consistent of the three teams over the two halves of the season.  Second, the change for all three teams has been driven far more by pitching and defense than by offense.  Still, offense has played a part, and is a good place to start.

There are four basic offensive components we’ll look at: batting average on balls in play (which will show whether hits are falling in more or less), total bases per hit (which will show power), walk rate, and strikeout rate.  Essentially, these stats comprise the basic components of on-base percentage and slugging—HR/AB is also useful here, but none of the three teams changed their HR/AB rate more than three percent, so it has not been a significant factor.  Here is what Seattle has done in those stats:

Seattle    AVG    OBP    SLG   BABIP   TB/H   BB/(BB+AB)  SO/AB
Pre-AS    .277   .355   .426   .313    1.54     .105       .174
Post-AS   .275   .341   .423   .312    1.54     .090       .182
Change    -0.7%  -3.9%  -0.7%  -0.3%    0.3%   -13.9%       4.2%

A small increase in strikeouts didn’t help, but clearly Seattle’s run scoring difficulties stemmed from a large decrease in walks.  In the American League, only Cleveland experienced a greater change in walk rate than Seattle; they decreased by 20%.

Anaheim had a much smaller change:

Anaheim    AVG    OBP    SLG   BABIP   TB/H   BB/(BB+AB)  SO/AB
Pre-AS    .278   .337   .429   .304    1.54     .075       .142
Post-AS   .292   .352   .437   .318    1.49     .077       .135
Change     5.0%   4.5%   1.9%   4.6%   -3.0%     3.3%      -4.9%

With a small increase in batting average on balls in play and a decrease from an already very low strikeout rate, the Angels were able to increase their batting average, and with it, their OBP and slugging (though the increase in slugging was somewhat reduced by a small decrease in total bases per hit).  Though Anaheim improved their raw batting stats, they didn’t do so enough to keep their runs scored per game from actually dropping.

Oakland had the biggest swing in offensive performance, which resulted almost entirely from one factor:

Oakland    AVG    OBP    SLG   BABIP   TB/H   BB/(BB+AB)  SO/AB
Pre-AS    .258   .335   .429   .289    1.66     .096       .195
Post-AS   .270   .346   .447   .287    1.65     .096       .150
Change     4.7%   3.3%   4.2%  -0.6%   -0.4%    -0.1%     -23.0%

After the All-Star break, the A’s cut their strikeout rate by a massive 23% while essentially keeping everything else constant.  That added nearly half a run per game for Oakland.  The next largest decrease in strikeout rate in the AL was by the Baltimore Orioles, who cut theirs 9.8%.  No team came close to the reduction the A’s made.

These changes basically reversed the AL West contenders in terms of offensive strength.  However, the change in pitching and defense was much greater.  Here are how each team’s opponents have fared in those same categories:

Vs. SEA    AVG    OBP    SLG   BABIP   TB/H   BB/(BB+AB)  SO/AB    HR/AB
Pre-AS    .244   .303   .393   .274    1.61     .073       .195     .032
Post-AS   .276   .330   .440   .309    1.60     .071       .184     .034
Change    13.1%   8.9%  12.0%  12.5%   -1.0%    -3.2%      -5.8%     8.6%

Vs. ANA    AVG    OBP    SLG   BABIP   TB/H   BB/(BB+AB)  SO/AB    HR/AB
Pre-AS    .256   .323   .418   .283    1.63     .087       .178     .032
Post-AS   .235   .299   .354   .263    1.51     .079       .178     .026
Change    -8.2%  -7.4% -15.3%  -7.3%   -7.8%    -9.1%      -0.4%   -19.6%

Vs. OAK    AVG    OBP    SLG   BABIP   TB/H   BB/(BB+AB)  SO/AB    HR/AB
Pre-AS    .267   .331   .406   .306    1.52     .083       .187     .025
Post-AS   .231   .293   .353   .261    1.53     .072       .182     .024
Change   -13.5% -11.5% -13.1% -14.8%    0.1%   -13.3%      -2.8%    -6.1%

The vast majority of the difference for Seattle and Oakland (and a large factor for Anaheim) has been the result of batting average on balls in play.  While strikeouts, home runs, and walks have contributed, they explain only a small part of the change.  Compare the actual ERA each team has posted to a quick approximation of their DIPS ERA, which is based on walks, strikeouts, and home runs:

Team            ERA   DIPS ERA
SEA Pre-AS     3.67     4.16
SEA Post-AS    4.74     4.33
Change         29.2%     4.1%

ANA Pre-AS     3.98     4.49
ANA Post-AS    3.22     4.11
Change        -19.1%    -8.5%

OAK Pre-AS     4.09     4.05
OAK Post-AS    3.05     3.89
Change        -25.4%    -4.1%

It appears that much, if not most, of the cause of the shift in the AL West was either chance, defense, or some combination of the two.  For Seattle and Oakland, the changes in BABIP allowed were quite severe; in fact, they were the two greatest changes in the American League:

        Change in
Team  BABIP Allowed
SEA       12.5%
NYY       12.4%
KCR        9.2%
BAL        7.0%
BOS        5.5%
TEX        4.6%
DET        1.2%
CWS       -0.3%
CLE       -0.5%
TBD       -0.6%
TOR       -1.1%
ANA       -7.3%
MIN       -8.7%
OAK      -14.8%

If the variation is the result of chance, it would certainly be surprising to have two random changes of that magnitude affecting a pennant race.  However, it also seems unlikely for both teams’ defensive performance to have changed so severely.

One final note: While Oakland experienced a similar improvement in record in 2001, the change came about in a completely different way.  Offensively, they saw an enormous increase in HR/AB (33.7%), with lesser improvements in BABIP (9.0%) and walk rate (10.8%).  They only decreased their strikeouts by 2.7%.  Defensively, the biggest change was also home runs (-35.9%), with a much smaller decrease in walk rate (-6.1%).  BABIP (-3.1%) and strikeout rate (-3.5%) played relatively minor roles.  Oakland’s turnaround in 2002 appears essentially unrelated to their turnaround in 2001.