This week, Baseball America released the data for minor league park effects over the past three seasons. If you follow the Minor League Wraps, you know that I've said things like "Peoria is tough to hit in, especially in April" or that Albuquerque is "Coors Field on steroids." (Just a note: they are introducing a humidor there this season, so things might get a little better.) But BA has just completed what I think is the most complete look at exactly how much minor league players' statistics are being affected by the parks they play in.
Baseball America looked at five categories for all of the full-season leagues: runs, hits, home runs, strikeouts and walks. They then looked at how each park influenced each category. Minor league parks are especially good laboratories for such data, since the roster turnover is extremely high.
Also, they looked at how the leagues ranked overall in production in these categories. Since there isn't any interleague play in the minors, they can't quantify exactly how much each league affects offense as a whole, but they can rank each league by how many runs they have in an average game, how many hits, etc. Again, because of the extreme roster turnover in these leagues, such numbers are unlikely to be significantly impacted by roster construction.
To sum it all up, Baseball America published the runs, hits and home runs per game for each park over a period of 2010 to 2012. They also produced a park factor number which indicates how much the park increase or decreases runs scored. To take my favorite example of Albuquerque, its park factor number is 1.229, meaning it increases runs scored by roughly 23%
Additionally, they produced a standard deviation for each league in runs scored, indicating how wide a spread between the parks in each league is. Unsurprisingly, the Pacific Coast League has the largest standard deviation between the parks at 1.88.
Enough of the math. Just tell me what the park effects of the Cubs affiliates are!
Fair enough. The Cubs four full-season teams (Sorry, Boise. They didn't run the numbers for you), shows that for the most part, the Cubs minor league parks favor pitching. There is one significant exception, however, and one pitcher's park is in an extreme hitter's league.
Here are the affiliates from low to high (because hopefully that's the direction a player is moving):
Midwest League: Peoria/Kane County
The Midwest League is a pitcher's league. They rank ninth out of the ten minor leagues in home per game (1.24) and dead last in the number of hits per game. (16.96). They shoot up to fifth in runs scored per game (9.13), a contradiction that can likely be explained by the number of walks and errors committed at the lowest level of the full-season minors. (The other Low-A league, the South Atlantic League, shows a similar disconnect between hits, home runs and run scored.)
The parks in the Midwest League uniformly favor the pitcher with the lowest SD (0.48) of park effects among the ten minor leagues.
Peoria was a pitcher's park in a pitcher's league, which is why we need to be cautious about overreacting to good pitching performances and poor hitting performances there. Peoria ranks 12 out of 16 teams in the Midwest League with a park factor of 0.968. (Meaning that offense is reduced by about three percent.)
But the Cubs are moving to Kane County this season. Are the Cubs hitters going to catch a break there? Nope. Peoria and Kane County are almost identical parks. They both averaged 8.73 runs per game over the past three seasons. Peoria is a slightly better place to hit a home run and Kane County is a slightly better place to get a base hit. Kane County's park factor is 0.978, meaning runs are going to be reduced by only 2% rather than 3%.
The move to Kane County may have other positive effects, but it's not going to change the way players perform in any significant way.
Florida State League: Daytona
Things get no better for the Cubs hitters in the Florida State League. The FSL has long had a reputation as a pitcher's league, and the numbers bear it out. The only league with fewer runs per game than the Midwest League is the FSL, who rank dead last with 1.13. The only league that has fewer hits per game than the 17.03 in the FSL is the Midwest League.
The Florida State League ranks dead last in runs per game at 8.58. I'm sure the major league-quality fields (most teams play at spring training sites) cut errors down a lot.
At least Jackie Robinson Ballpark in Daytona Beach is a slight hitter's park within the league. It averages 9.00 runs per game. It has a park factor of 1.015, meaning offense increases by about 1.5%. Daytona is better for home runs than batting average.
Southern League: Tennessee
Here's where Cub hitters get a bit of a break. With the Florida State League being the worst league for scoring in the minors and the Midwest League being the second-worst, things don't get much better there since the Southern League is in eighth place out of ten leagues for runs scored. Yes, the Cubs three lowest full-season affiliates are all in the top three leagues for pitchers.
But among Southern League parks, Smokies Park is a veritable launching pad. Games there average 9.92 runs per game, which is first by a large margin. Second place is Chattanooga at 9.52, and the Smokies play a lot of games there, too. Smokies Park is first in hits and first in home runs in the Southern League, again by a large margin both times. Its park factor is 1.079, meaning offense increases there by about eight percent.
So while the Smokies pitching staff gets a break on the road, hitters rule the roost in Eastern Tennessee.
Pacific Coast League: Iowa
The glories of the PCL are well known. The Pacific Coast League isn't the best league for offense (that would be its little brother, the California League), but it still produces a whopping 10.69 runs per game. It even ranks first in hits per game (19.44) and home runs per game (1.94) as the Cal League presumable produces more runs as a result of more free bases, more errors and more aggressive baserunning.
But the PCL is also the most diverse ecosystem in the minor leagues. The standard deviation between parks is a whopping 1.88. Only the Cal League, again, comes close to that amount of diversity.
This comes into play for the Iowa Cubs because the real launching pads in the PCL are in the West. The top six parks in the PCL are Albuquerque, Colorado Springs, Reno, Las Vegas, Salt Lake and Tuscon, and all of those teams are in the other conference. The Iowa Cubs simply don't play a lot of games against those teams.
Two of the teams within their division, Nashville and Memphis, rank 14th and 15th in the sixteen-team league in runs scored per game. The other team is Omaha who ranks eighth, but that is based on limited data as their new ballpark is only two years old.
As far as Principal Park itself goes, it fits right in with the rest of the teams in the I-Cubs division. It ranks 12th in the league with 9.33 runs per game. Only Oklahoma City is a worse park to hit a home run in by any significant margin. The park effect is .917, meaning that Principal Park decreases offense by a little over 8% relative to the rest of the league.
So while the Pacific Coast League is a hitter's league, the part of it Iowa plays in is a pretty good pitcher's division.
So for the most part, the parks of the Cubs affiliates aren't doing the Cubs hitting prospects any favors. BA didn't rank the Northwest League, but Boise is generally considered to be a hitter's park in a hitter's league. So when hitters who put up big numbers there go to Peoria (and now, Kane County) and struggle, it's not always just that they're having trouble against better competition. Some of it is that their numbers were inflated in Boise and had all the air let out and more in the Midwest League. Make no mistake about it: Kane County, especially early in the year when it's cold, is going to be a hard place for a player to get a hit.
The one break the Cubs hitters get is Smokies Park. It's an axiom in the business that the toughest promotion, other than to the majors, is from High-A to Double-A. For Cub hitters, they get a break in the adjustment by leaving the salt air of Florida for the relatively dry, thin air (Smokies Park is at about 900 feet above sea level) of Sevierville. For the Cubs pitchers, the transition is all that much harder. But they had been getting a break all the way before then, and they will again, to a certain degree, in Iowa.