Understanding the impact
of Coors Field
By: Tom Tippett
Date: July 16, 1996
As you know, offense goes sky high in Coors Field. We can see that
in the park factors and the home/road splits for individual players.
Here are some hitting stats for the NL as a whole (including Coors),
Coors only, the NL without Coors, the Coors numbers prorated to 700
plate appearances, and park-adjusted norms for players who play half
their games at Coors.
NL w/o Per Half
Total Coors Coors 700PA Coors
G 1007 72 935 162 162
AB 69049 5194 63855 638 638
H 18184 1637 16547 201 183
2B 3367 305 3062 37 34
3B 418 59 359 7 5
HR 1917 241 1676 30 23
W 6668 509 6159 62 62
K 13309 880 12429 108 116
R 9329 975 8354 120 102
AVG .263 .315 .259 .315 .287
SPC .408 .536 .397 .536 .464
Runs/Tm/Gm 4.63 6.77 4.47 5.62
What can we learn from this? Quite a bit, actually:
- If Coors Field wasn't part of the 1995 NL, the league batting average
would have been four points lower and the slugging average would have
gone down by eleven points. If you're playing in a Diamond Mind draft
league that uses NL players but doesn't include Coors, you can expect
your league averages to go down by the same amount.
- Similarly, if Coors was not included in your draft league, the league
average runs per game would go down by .16 runs. Factor in the unearned
runs, and you can expect to see the league ERA go down by fourteen
- The fourth column is the most compelling. It says that an average
hitter with the opportunity to play 162 games in Coors Field would
pile up MVP-type numbers. And this is not Barry Bonds we're talking
about. This is the average hitter, including pitchers, middle
infielders and September callups. Everybody.
- The fifth column helps us evaluate real-life players who played
in Colorado last year. It's a 50/50 weighting of the Coors numbers
in column two and the non-Coors numbers in column three, prorated
to 700 plate appearances. These are the figures that the average hitter
would compile in 81 games at Coors and 81 games at the other thirteen
parks. In other words, any Rockies player who posted those numbers
(or the equivalent for the amount of playing time they really had)
is merely average. If you move them to another park, you can expect
their numbers to drop quite significantly. Keep this in mind when
you evaluate your draft choices next time around.
- Several members of the 1995 Rockies posted great numbers that were
largely dismissed because of the park effect. Was this fair? Looked
at in this light, it's clear that Burks had a below-average year.
Castilla and Galarraga were a little above average. Bichette had a
very good year and deserved consideration for the MVP award. Even
if he played in the average non-Coors park, he would have hit about
.312 with a slugging average of .553, numbers that compare favorably
with Bonds, Gant, Sanders, Sosa, and Conine. I'd make a roster spot
available for him anytime.
- If the Rockies had played in a neutral park, their pitching staff
would have finished around fourth in the league in ERA and their hitters
would have been around ninth. So although they ranked last in pitching
and first in hitting, it was superior pitching that carried them to
Copyright © 1996. Diamond Mind, Inc. All rights reserved.