Over at Beyond the Box Score, they published a really neat article calculating the park factors for the past five years of all the major league ballparks. Instead of focusing just on run environment, the author digs into all the relevant events in the game like home runs, doubles, and even walks and strikeouts. Here are the numbers he came up with for Houston:
| Team | Years | R/G | PA/G | SO/PA | BB/PA | 1B/BIP | 2B/BIP | 3B/BIP | HR/BIP | SB/G | CS/G | TB/BIP | BIP/PA |
| HOU | 5 | 0.98 | 1.00 | 1.03 | 0.99 | 0.99 | 0.99 | 1.07 | 1.06 | 0.99 | 0.96 | 1.01 | 0.99 |
That confirms a lot of what we have come to know over the years. MMP plays pretty neutral in terms of runs scored, after pitchers learned how to use that deep outfield. There are more doubles and home runs hit there, but fewer singles and doubles (just slightly) than the league average.
What I'm interested in doing is comparing these numbers to Colorado and Boston to see in what areas Bill Hall and Clint Barmes may improve upon in 2011, just by switching parks. Obviously, there are other factors at work, like aging, pitching and the like, but this should give us a place to start with these guys.
First, let's look at both Colorado and Boston's park factors:
| Team | Years | R/G | PA/G | SO/PA | BB/PA | 1B/BIP | 2B/BIP | 3B/BIP | HR/BIP | SB/G | CS/G | TB/BIP | BIP/PA |
| COL | 5 | 1.09 | 1.01 | 0.95 | 0.98 | 1.02 | 1.04 | 1.18 | 1.08 | 0.98 | 0.99 | 1.05 | 1.02 |
| BOS | 5 | 1.04 | 1.00 | 0.98 | 0.99 | 1.00 | 1.16 | 0.95 | 0.93 | 0.95 | 0.97 | 1.01 | 1.01 |
Both have a full five years of data, just like MMP. In each case, the run environment is significantly better than in Houston. But, since runs have very little to do with player skill and more to do with lineup construction, I don't know that the switch in parks can be directly linked to lower or higher runs scored for each guy next season.
Both parks also have slightly higher factors for singles. Boston and Houston are very close, while Colorado is slightly higher. I'd expect Barmes average to drop a little more and Hall's to stay about the same, all things being equal. Because of the Green Monster, Fenway has a huge park factor for doubles. That's where Hall will probably take the biggest hit in his 2011 numbers.
However, Fenway was also very unforgiving on home runs. Only four parks had lower factors on home runs per ball in play than Fenway did. Since Houston's is the eighth-highest, we can reasonably expect Hall's home run total to uptick some. Unlike Pedro Feliz last season, who went from the seventh-highest park factor to the eighth), there is some basis for making a wild claim like that.
Barmes, though, may suffer from a drop across the board. Every single offensive category was higher in Colorado than it will be in Houston. His batting average, his slugging percentage, his total bases all should fall either a little or a lot in 2011. Again, that's to be expected, as we all knew his home/road splits weren't great last season.
Neither player should walk much more just based on park factor. There was some discussion in the original article about whether park factors really do influence strikeouts and walks. A hitter prone to strikeouts will whiff no matter where they are hitting. But, it's worth noting that both of these guys are moving from parks with slightly lower strikeout totals than average to a park with a higher-than-average number. That may affect Hall more than Barmes, as he's been more prone to the "K" than Barmes has in his career.
The only other thing we may be able to glean is that MMP has a slightly higher stolen base rate than either other park. With Barmes, I'm not sure if it'll up his numbers, but I'm pretty sure Hall could hit double-digit steals for the first time since 2005.
What do you think? Is there anything else we can learn from this? Does this affect your expectations for these two players? Are you surprised by any of the MMP factors?