While sporadically entering data
for a follow up column on the Walk Gap,
the following arrived in my inbox. Suffice to say Mike Rice does more justice to
the topic than I can, so I’ll turn it today’s column over to him:

I read your article on the "Walk Gap" last week and decided to do
a little research, using the data at I used the
1995-2000 seasons--the post-strike era--and found that there is a very
strong, positive correlation between Walk Gap and Run Differential. On
average, the correlation was 72.5% in the American League and 78.8% for the
National League.

What I did was figure the difference between walks and walks allowed for
each team, then ranked them from greatest to smallest. I then figured the
difference between runs scored and runs allowed for each team and ranked
them the same way. I then ran regressions, with the team's wins as the
dependent variable and Walk Gap rank as the independent variable. I did the
same exercise using run-differential rank as the independent variable also.

There is a pretty good relationship in most years. The t-scores are
significant and the R-squared is pretty high. The three seasons that don't
work are the American League in 2000 and 1997 and the National League in
1996. However when you take a team's average Walk Gap rank and their average
run-differential rank and their winning percentage for the six-year period,
you see that the teams with the highest winning percentages have the best
rankings in both Walk Gap and run differential. The only outlier is Oakland.
Year by year, you can see the effect of Billy Beane and what he has been
preaching and the year in which it started to take effect.

Mike, thanks for taking the time to do the legwork, and for allowing me to
share it with our readers.

Mike included an Excel file with his research, and it’s clear that over a
period of years, the Walk Gap is a pretty significant indicator of success.
As he points out, the A’s have had good walk differentials in the
post-strike era, but only recently have had success to match.

From the spreadsheet, here are are average Walk Gap ranks, run-differential
ranks and aggregate winning percentages of teams since 1995:

             Avg. Rank
Team    Walk Gap  Run +/-   Pct.

NYY 3.00 3.17 .594 CLE 3.33 2.33 .589 BOS 6.83 4.67 .545 SEA 6.33 5.00 .525 TEX 7.00 6.67 .519 BAL 7.17 6.17 .512 CHW 8.50 6.83 .507 ANA 9.83 7.83 .492 OAK 5.00 8.33 .485 TOR 10.50 9.00 .483 MIL 12.00 9.00 .478 KCR 8.67 11.17 .447 DET 9.17 11.00 .425 MIN 7.83 12.33 .424 TBD 11.67 12.00 .414

Avg. Rank Team Walk Gap Run +/- Pct.

ATL 2.50 1.83 .619 HOU 2.50 5.00 .538 NYM 5.67 5.67 .531 LAD 9.17 5.67 .526 CIN 8.33 6.50 .524 SFG 5.00 7.50 .520 ARI 7.00 8.00 .514 SDP 6.17 7.83 .508 STL 7.00 7.17 .500 COL 11.17 8.00 .497 CHC 10.33 10.17 .460 FLA 12.33 10.50 .458 MIL 10.00 12.33 .456 MON 11.33 11.17 .453 PIT 10.83 11.17 .447 PHI 9.67 12.17 .441

One of the last things at which I want to look is whether the Walk Gap is an
indicator of whether a team will outperform its Pythagorean record. It’s not
clear from the data Mike sent in, and it is something about which I’ve been
wondering. I’ll keep plugging in my own numbers and see if anything comes of

Joe Sheehan is an author of Baseball Prospectus. Contact him by

clicking here

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