July 17, 2002
The Daily Prospectus
Back Into the Gap
Last year, I started messing around with something I call the Walk Gap, which is just the difference between a team's walks drawn and walks allowed. Because we've spent so much time hammering home the importance of plate discipline and throwing strikes, I thought this might be a good indicator of team success.
After I wrote the article, reader Mike Rice ran with the concept and discovered that there was a strong positive correlation between the Walk Gap and run differential for the 1995-2000 seasons, .72 in the AL and .79 in the NL.
With that in mind, I dug up the spreadsheet and plugged in the numbers for 2002 to date to see if control of the strike zone, both on the mound and at the plate, is again showing up on the scoreboard.
Team Walk Gap Rank Run +/- Rank Yankees +124 1 +166 1 Mariners +123 2 +115 3 Red Sox +51 3 +121 2 Athletics +51 3 +37 5 Twins +25 5 +23 6 White Sox +2 6 +11 7 Indians -12 7 -74 12 Royals -21 8 -68 11 Rangers -34 9 -29 9 Angels -35 10 84 4 Blue Jays -41 11 -60 10 Orioles -56 12 6 8 Tigers -62 13 -140 14 Devil Rays -83 14 -131 13
Team Walk Gap Rank Run +/- Rank Diamondbacks +132 1 +53 3 Expos +37 2 -8 8 Giants +32 3 +101 1 Phillies +28 4 -35 12 Reds +22 5 -14 9 Padres +20 6 -99 16 Astros +7 7 +11 7 Cardinals +3 8 +47 4 Cubs -5 9 -33 11 Marlins -20 10 -21 10 Rockies -24 11 -50 13 Mets -33 12 +26 6 Braves -35 13 +85 2 Dodgers -46 14 +44 5 Pirates -65 15 -51 14 Brewers -85 16 -81 15
As was the case last year, the relationship in the American League is much more clear than in the National League. I'm inclined to believe that this has to do with the separation in the AL right now; if you take any positive statistic, I think you'd find the 6-7 AL teams that are actively trying to compete at the top end, with the others all in the bottom half. In the NL, there are fewer teams playing for the future, and more trying to win in 2002, all getting there in different ways.
Just two AL teams have a run differential that runs counter to their Walk Gap: the Angels, who are making up for a lack of walks by hitting .276 (third in the AL), and the Orioles, who are just barely positive despite the league's third-worst Walk Gap. In the NL, though, the figures are over the place.
Put another way, the correlation between Walk Gap and run differential in the AL is a whopping .82. In the NL, it's just .29. That's an enormous difference, and causes me to question whether this method is all that important in measuring team quality, or whether something strange is going on.
On a hunch, I pulled intentional walks from the data. In the AL, this only changed the Blue Jays' ranking, moving them up a few spots, while maintaining a negative Walk Gap. The correlation slipped from .82 to .77. In the NL, though, it caused a bit more movement, most notably making the Cardinals and Giants (gee, I wonder why) negative Walk Gap teams. The correlation between the Unintentional Walk Gap and the differential in the NL is .05, which strongly implies that there is no correlation between the UWG and run differential in the National League.
That doesn't make much sense to me, so I'm throwing it out there. What would explain these numbers, other than the obvious--"Joe doesn't know how to use Excel." Is the Walk Gap just a gimmick stat? If it has importance, why would there be such a disparity in its significance across the league? More to the point, why is there such a disparity in the two correlations?
I'm a bit far afield here, so I look forward to seeing what BP readers have to say on the subject