Baseball By Paul

It all started with a hypothesis from a friend, Brian Fleischer, on a website I frequent:

“For the last few years at least, Coors has not become a launching pad until late April or May. Presumably because of the residual cold weather, it’s not such a bad idea to start Rockies pitchers or opposing pitchers at Coors for the first two or three weeks of the season.”

It sounded reasonable enough to me. First off, Fleischer is no idiot and he generally puts forth well-founded ideas. I found this one no different and decided that I would check the numbers and prove that it was right. What I found in the 2000-2004 data shocked me, to say the least. It turns out that the idea of residual cold weather in the early spring benefiting the pitchers in Coors Field was false:

In fact, April has the highest runs per game total at 13.63. From there, one of the participants in the discussion asked about just Colorado Rockies’ starters and their ability to keep runs down in the early months.

Now we see that the Rockies’ pitchers are better in April and May than all other months except August, but given that August is the second warmest month, it is difficult to equate their success (relatively speaking) to the cooler temperatures. Next, there was a question as to what effect the humidor in Colorado had on the findings. The ball humidor was used in Colorado to deaden the ball and thus tame the outrageous figures put up in Denver’s Coors Field. At this point, I was no longer expecting anything from the April-May vs. rest of the season analysis, rather I was just interested to see the patterns, if any, that runs were scored in Coors Field. Here’s a look at the pre and post-humidor breakdowns:

Four months showed a drop in the humidor era, but two others showed spikes, one large and the other insignificant in the grand scheme. Overall, the humidor’s effect from 2000 to 2004 dropped the runs per game by about one. The precise total going from 13.33 runs per game to 12.31 runs per game.

So that was it, as far as I was concerned. Any idea of a specific time period being a good time to pitch in Coors Field appears to be non-existent. Fast forward to today when both the "Coors Field Mystic" and "Coors Field Cold Weather Theory" were challenged in the same forum by two new members. One suggested that the idea of opting not to pitch your pitchers in Coors for your fantasy baseball team may be over hyped, while the other once again surmised that Coors Field produces less runs in the early season due to the cooler weather. I don’t mention both to deride, rather to point out that these misconceptions are still being bandied about.

The latter member stated that a simple month-by-month breakdown of the four years cobbled together wasn’t enough to convince him that there is no basis for starting pitchers in Coors in April or May due to cooler. To him, as well as all of you, I present a yearly month-by-month breakdown with average temperatures for each year. As with the other data, 2005 is not yet fully available for analysis, so I’ll continue with 2000-2004:

Year-to-year monthly temperatures remain consistent and still I see nothing that suggests there is ever a time when success can be expected in Coors Field. The outliers are the opponents’ runs per game of 2002. I feel they may’ve been tweaking with the humidor usage and overdid it in April and May before spiking back the wrong way in June and evening it out the rest of the year. It also could have been something as simple as scheduling, a point brought up by the member with whom I was discussing the issue. In fact, he mentioned that scheduling and lineup factors would be present throughout the data and while I understand that the teams change, oftentimes significantly, from year-to-year, I don’t believe that it is enough to skew the data over the course of the five year sampling. It was mentioned that the lineup in 2005-06 wasn’t up to par from the previous years, but I would posit that it is as good as, if not better, than the 2003 and 2004 lineups. For the record, only the 2000 Rockies team of all analyzed were over .500 (82-80).

After looking at the five years worth of data with regards to runs being score in Coors Field, I conclude that:

• April’s cooler weather has no lowering effect on runs scored in Coors Field.
• There is no specific month in which starting pitchers at Coors Field are more successful in comparison to the others.
• At no time should you use starting pitchers at Coors Field in your fantasy league if you can avoid it.

Posted on Tuesday: 04.18.2006 at 12:09 am in Analysis   |  RSS feed |   Reply   |   Trackback URL