Doctoring the Numbers

Coors Field

Theories on how altitude makes Coors Field such a great hitters' park abound, as do theories as to why Rockies' hitters seem to do so poorly on the road. The theory we like is that their hitters simply suck, but not everyone sees it that way. Colorado third baseman Jeff Cirillo had this to say recently:

"We all know how great a hitters' park Coors is, because of the way
the ball travels and the fact that curveballs don't break very well. But I
think the biggest factor in our home/road problems is that at Coors you
don't get that late movement on fastballs. So at home, we're hitting
straight fastballs. On the road, it's hard in five or six days to adjust to
that late movement, which is the difference between a line drive and a
popup."

Does Coors Field, by its very nature, spoil the hitters who get to play there 81 times a year and make it more difficult for them to adjust to sea level than their opponents?

It's an interesting theory, and a testable one. If Cirillo is right--if it does take time for hitters to adjust to sea-level baseball after a steady diet of Don Wengert Specials--then we should see the Rockies' performance on the road improve the longer they are away from home. In other words, the Rockies should hit relatively poorly on their first game on the road compared to their performance in the seventh or eighth game of a road trip.

Let's look at the numbers. So far this season, this is how the Rockies have fared on the road:

Game # Trips AVG OBP SLG OPS

1 7 .267 .348 .406 754 2 7 .215 .271 .326 597 3 7 .272 .330 .398 728 4 7 .190 .263 .312 575 5 7 .221 .315 .301 616 6 4 .279 .342 .368 700 7 2 .200 .290 .345 635 8 2 .273 .377 .318 695 9 2 .190 .239 .333 572 10 1 .257 .316 .400 716 11 1 .286 .306 .314 620

"Trips" refers to how many road trips the Rockies have played that number of games. For example, every one of the Rockies' seven road trips this season has lasted at least five games; only two went longer than six games and only one went longer than nine games.

Gee, don't you just hate it when the data goes directly against your theory? The Rockies have hit best on the first game of a road trip; ignoring the one-game sample at game 10, the Rockies have cleared a 700 OPS in only one other situation, the third game of a road trip. When you consider that every team in baseball has an OPS above 720, the Rockies' performance on the road--in any game--is simply inexcusable.

Looking back to 1998 and 1999, here are the Rockies' combined road stats for those years, broken down by game:

Game # Trips AVG OBP SLG OPS

1 24 .260 .315 .403 718 2 24 .247 .306 .410 716 3 23 .251 .308 .367 675 4 19 .263 .321 .403 724 5 19 .247 .300 .403 703 6 16 .237 .289 .383 672 7 10 .242 .288 .373 661 8 8 .233 .297 .374 671 9 6 .216 .259 .385 644 10 4 .210 .280 .363 643 11+ 7 .312 .363 .435 798

Well, if you really want to believe, you can point to the Rockies' performance from the 11th game of a road trip on--a total sample of just seven games--and say that yes, after nearly two weeks they do adjust to sea level and start hitting.

And if you close your eyes tight and click your heels together three times....

But otherwise, just like the data from this season, it appears that, if anything, the Rockies hit worse the longer they are on the road. Sorry, Jeff. It sounded like a really good alibi.

Just for kicks, let's turn this theory around and see how the Rockies do at various points of a homestand. If Cirillo's theory had any merit, then it would take the Rockies a little while to adjust to the fact that they no longer have to be on guard for a knee-bending curveball at home, and so we might expect them to, again, hit better as the homestand progressed.

The numbers for this season:

Game # Trips AVG OBP SLG OPS

1 7 .340 .423 .576 999 2 7 .294 .383 .528 911 3 7 .331 .405 .556 961 4 5 .358 .426 .602 1028 5 4 .315 .424 .591 1015 6 4 .400 .435 .566 1001 7 3 .427 .515 .718 1233 8 2 .432 .489 .716 1205 9 1 .324 .405 .676 1071

While the sample size is small, there does appear to be a significant improvement in the Rockies' offense in later stages of a homestand. Let's look at the data from 1998-99:

Game # Trips AVG OBP SLG OPS

1 24 .308 .370 .529 899 2 24 .321 .388 .499 887 3 23 .350 .414 .589 1003 4 21 .325 .375 .540 915 5 20 .340 .389 .548 937 6 17 .327 .382 .533 915 7 11 .355 .397 .593 990 8 7 .313 .364 .500 864 9 6 .283 .335 .487 822 10+ 9 .272 .331 .430 761

This data shows something completely different: while the Rockies do appear to improve early on in a homestand, the peak is bimodal, at game 3 and game 7, and then there is a significant decline in the team's hitting from the eighth game of a homestand on. The sample sizes are still not large enough to completely remove random variation, but there is little compelling evidence here that the Rockies significantly and consistently improve during a homestand. And the evidence on the road suggests, if anything, a mild decline with time.

The conclusion? The problem with the Rockies' hitters is not that they get fat on a steady diet of straight pitches at home, and just need time to cure their problems at sea level.

No, the problem appears to be this: their hitters simply suck.

Rany Jazayerli, M.D., can be reached at ranyj@baseballprospectus.com.

Rany Jazayerli is an author of Baseball Prospectus.
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Keith Woolner is an author of Baseball Prospectus.
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