One of the most fascinating aspects of professional baseball, particularly at the minor league level, is the diversity of ballparks, how they play for hitters and pitchers, and the role that plays in the outcome of various events.
Depending on the park's features, a team may gain an advantage from righthanded power hitters taking aim at a short left-field porch, speedy outfielders covering a vast territory, or groundball pitchers paired with a slow playing surface limiting the number of hits.
We often talk in generalities when discussing minor league parks, focusing on the league in which a team plays. For example, we might say the California League is a hitter's league. Or the Florida State League favors pitchers. But to what extent are those statements true? Which parks in those leagues push the needle the farthest? Which parks are the exceptions?
To answer those questions and more, Baseball America gathered home and road data for all 120 full-season minor league teams dating back to 2010. Distinct patterns emerge over the course of three seasons—encompassing more than 200 home games and 200 road games for most teams—and differences in weather conditions and varying talent levels from year to year tend to even out.
The bulk of our presentation considers only how teams—that would be the home team and its opponents—fared in each of the 120 ballparks. This way we can stack up how parks compare with one another in terms of runs, hits and home runs per game over the past three years. (Exceptions are noted when a sample does not stretch to three years.)
The data allowed us to isolate five categories—runs, hits, home runs, walks and strikeouts—for batters and pitchers at each minor league park and scale them to games played.
The home run may be baseball's ultimate weapon, but the strongest correlation between categories exists between a park's hits and its runs scored. That is to say that parks featuring many hits tend to feature many runs. The opposite also is true. Parks that feature few hits typically feature few runs.
In statistical analysis, it's important to determine the correlation between two sets of numbers—in other words, whether one number is meaningful in predicting another. A fancy term for this is the "coefficient of determination," also called R-squared, which is represented as a number between zero and one, with one being perfectly predictive. An R-squared of .50 indicates a good correlation, so the .89 R-squared between hits and runs is almost startlingly strong.
Moderate to strong correlations exist between hits and home runs (.41) and home runs and runs (.48). No other comparisons yielded a positive correlation, with walks and strikeouts (.00) and home runs and strikeouts (.01) showing particularly weak correlations.
Taking things league by league, we'll show you the runs, hits and home runs per game at each park for 2010-12. You can compare the individual park rates with the league rates to gain a frame of reference. The standard deviation for runs gives you an idea of park diversity in each league. A low number indicates that most parks are clustered around average, while a higher number indicates a wide array of park contexts.
The park factor for runs (PF-R) is listed last. A reading of 1.000 is exactly average and assumes that a player will play half his games at home. High Class A High Desert has the highest PF-R (1.228) in the full-season minors, indicating that Mavericks batters receive roughly a 23 percent boost by playing half their games at that park. On the other end of the spectrum, low Class A Savannah's .880 PF-R indicates that batters are penalized about 12 percent based on their home park.
To use the park factors, take a batter's runs created per game or a pitcher's runs allowed per game (or whatever your metrics of choice might be) and divide by his park factor. This will give you a crude a park-adjusted rate of production for any minor league player.
International League (Triple-A)
Runs per Game: 8.74 (9th out of 10). Hits per Game: 17.43 (4th).
Home Runs per Game: 1.67 (3rd). Standard Deviation in R/G: Low (0.73).
|Rates Per Park, 2010-120|
|* 2010-11 only|
Note: Scranton/W-B led a nomadic existence in 2012, playing all its "home" games at other parks, primarily Rochester, while PNC Field received a facelift. They begin play at renovated PNC Field this season as the Scranton/W-B RailRiders, having played as the Empire State Yankees in 2012 and the Scranton/W-B Yankees in 2011.
Launching Pad: Columbus, 2.46 HR/G (No. 4 out of 120 full-season teams)
Graveyard: Gwinnett, 1.35 HR/G (No. 77)
Hit Parade: Columbus, 19.03 H/G (No. 13)
Pitcher's Park: Scranton/W-B, 7.58 R/G (No. 3 fewest out of 120 full-season teams)
The Clippers, one of the league's flagship franchises, have enjoyed tremendous success since moving to their new park in 2009. They paced the IL in runs scored and home runs in each of the past two seasons, and they finished runner-up to Durham in 2010. The Indians affiliate has been wildly successful in that time, averaging 85 wins per season and winning the Triple-A National Championship Game in 2010 and 2011.
Columbus media director and franchise historian Joe Santry explains where all the offense comes from:
"In 2009 we moved from one of the largest fields in baseball (Cooper Stadium) to one of the smallest at Huntington Park. Because of the size of our lot, we had to bring the left field fence in 30 feet to 325. Right field is even closer at 318 feet, but the real secret to the hitting success at Huntington Park is the lack of foul territory.
"Because of the size of the city block which Huntington Park was built, the foul territory at its deepest is only 48 feet, and it tapers out to nothing. Hitters get a number of second chances when popups go in to the cozy stands. We also have a prevailing wind that usually blows out to left field."
Pacific Coast League (Triple-A)
Runs per Game: 10.69 (2nd out of 10). Hits per Game: 19.44 (1st).
Home Runs per Game: 1.94 (1st). Standard Deviation in R/G: Highest (1.88).
|Rates Per Park, 2010-12|
|* 2011-12 only|
Note: The Padres temporarily relocated their Triple-A affiliate from Portland, Ore., to Tucson in 2011, believing that they would eventually make a permanent home in Escondido, Calif., just north of San Diego. That plan is now dead, and the Padres intend to operate their Triple-A affiliate in El Paso beginning in 2014. Omaha simply moved from Rosenblatt Stadium to new Werner Park in 2011, changing their nickname from Royals to Storm Chasers.
Launching Pad: Albuquerque, 2.75 HR/G (No. 2)
Graveyard: Oklahoma City, 1.52 HR/G (No. 56)
Hit Parade: Albuquerque, 22.91 H/G (No. 2)
Pitcher's Park: New Orleans, 8.35 R/G (No. 22)
Isotopes Park, home of the Dodgers' Triple-A affiliate, is one of the most extreme hitter's parks in the minor leagues. In an effort to curb offense, the park will install a humidor this season. First used by the Rockies at Coors Field in 2002, the organization introduced it at its Triple-A Colorado Springs affiliate last year and saw dramatic results. Runs per game dropped from 15.78 in 2011 to 11.61 in 2012.
Albuquerque general manager John Traub explains why Isotopes Park is so offensive, and how the humidor could help:
"There are multiple factors which contribute to Isotopes Park being a hitter's park. First, we are in the high desert. At a mile high, the elevation and thin air contribute to balls going farther than they would in other parks. The low humidity makes the leather on the balls actually shrink and become harder and lighter, thus resulting in more distance off the bat. It is also quite windy here, particularly in the springtime. Prevailing west winds in the spring and south winds in the summer certainly play into balls flying out of here as well.
"The humidor will keep the balls at their intended weight and size and will hopefully even up the playing field relative to other ballparks. We can't do anything about the elevation or wind patterns, but hopefully the humidor will mean a reduction in cheap home runs."
IN FOCUS: Cheney Stadium, Tacoma
Tacoma director of communications Ben Spradling:
"Our outfield fences could certainly explain the substantial amount of home runs. Cheney underwent a $30 million stadium renovation following the 2010 season, and as part of the ballpark's facelift, the outfield fences were lowered from 17 feet to nine feet. After the first season in the new stadium (2011), we found that more home runs were hit at Cheney than in any of the previous seven years. Hits that previously would have been singles or doubles are now homers."
IN FOCUS: The Dell Diamond, Round Rock, Texas
Round Rock manager of baseball outreach (and former Express player) Matt Kata:
"(The higher-than-average rate of home runs) has a lot to do with the wind. The land is pretty flat around the stadium without many structures around, so there's not much to deter the wind. Also, our playing surface is sunk into the ground, so our concourse level is above the field and the wind blows right off the concourse—which is about 20-25 feet above the field. Interestingly enough, the ball typically blows out to left-center where the home run porch sits."
Eastern League (Double-A)
Runs per Game: 8.92 (6th out of 10). Hits per Game: 17.28 (6th).
Home Runs per Game: 1.52 (5th). Standard Deviation in R/G: Low (0.68).
|Rates Per Park, 2010-12|
Launching Pad: Reading, 2.03 HR/G (No. 12)
Graveyard: Altoona, 1.10 HR/G (No. 104)
Hit Parade: Portland, 18.50 H/G (No. 19)
Pitcher's Park: Richmond, 7.87 R/G (No. 8)
Runs per Game: 8.85 (8th out of 10). Hits per Game: 17.06 (8th).
Home Runs per Game: 1.36 (7th). Standard Deviation in R/G: Low (0.65).
|Rates Per Park, 2010-12|
|* 2012 only|
Note: The Reds moved their Southern League affiliate from Zebulon, N.C., to Pensacola, Fla., for the 2012 season.
Launching Pad: Tennessee, 1.72 HR/G (No. 38)
Graveyard: Birmingham, 0.78 HR/G (No. 116)
Hit Parade: Tennessee, 18.49 H/G (No. 21)
Pitcher's Park: Birmingham, 8.09 R/G (No. 14)
Birmingham has a rich baseball and ballpark history, which it honors each year with the Rickwood Classic—played at Rickwood Field, which opened in 1910. The next chapter in that history begins this season with the opening of Regions Field, which will also see the Barons return to downtown Birmingham after 25 years in the suburb of Hoover, Ala. Barons GM Jonathan Nelson gives his view on how the new park will play:
"Our previous park in Hoover was a pitcher's park. The dimensions were 340 feet down both lines, 385 to both alleys and 405 to center. In addition, the ball did not travel well because a wooded area went from left-center to right. We never received a lot of wind.
"Our new park should be more hitter-friendly. There are shortened fences in both left and right field. In working with the White Sox, it was important to them to keep the integrity of the right- and left-field power alleys—and also center field—the same."
Texas League (Double-A)
Runs per Game: 9.25 (4th out of 10). Hits per Game: 17.60 (3rd).
Home Runs per Game: 1.64 (4th). Standard Deviation in R/G: Moderate (1.04).
|Rates Per Park, 2010-12|
Launching Pad: Springfield, 2.35 HR/G (No. 6)
Graveyard: Arkansas, 1.00 HR/G (No. 106)
Hit Parade: Midland, 19.19 H/G (No. 11)
Pitcher's Park: Arkansas, 7.67 R/G (No. 4)
IN FOCUS: Dickey-Stephens Park, North Little Rock, Ark.
Travelers broadcaster Phil Elson discusses Arkansas' well-earned reputation as a pitcher's paradise, recounting tales of Angels prospects—especially righthanded ones—who have struggled to hit for power at Dickey-Stephens Park. Mark Trumbo hit six of 15 homers there in 2009, while Mike Trout hit four of his 11 homers there in 2011:
"The dimensions of the outfield, specifically the power alleys, are pretty deep, though not abnormally large. The combination of two very deep power alleys leads to a center-field area that is more spacious than most in the Texas League. Center field is 400 feet, while the left-center alley is 415 and the right-center alley is 390. The only real area of the field that could lean towards batters is down the right field line (330 feet) where there is a 4-foot fence.
"The ball just does not seem to have any carry whatsoever here. The only park like ours in the league is Wolff Stadium in San Antonio. I've seen guys just crush a belt-high fastball (here) and it's caught on the warning track in straightaway left field. The field is dug into the ground by about 13-15 feet, so perhaps this has something to do with that."
IN FOCUS: Arvest Ballpark, Springdale, Ark.
Separated by fewer than 200 miles, North Little Rock and Springdale, Ark., feature Texas League ballparks that play as almost if they're on different planets. Where the former favors pitchers, the latter tends to boost output by batters, particularly lefthanded ones. During the 2010 season, Eric Hosmer hit nine of 13 home runs and slugged .684 at home for Northwest Arkansas. Mike Moustakas slugged .894 (!) and belted 17 of 21 homers at home that same season.
Northwest Arkansas GM Eric Edelstein lists possible reasons for the inflated offense:
"Having been with the club since we designed the ballpark, I can tell you that we actually moved the fences back from the original design to create what we believed to be a neutral ballpark. Lines are 325 feet, and alleys are 375. In left field, the wall is 11 feet high, so we believed we were fair.
"Springdale sits at 1,300 feet above sea level, so perhaps a little altitude influence, and we do sit at the top of a hill in terms of topography, so there is a strong wind coming from the south to the north on most days."
California League (High Class A)
Runs per Game: 10.80 (1st out of 10). Hits per Game: 19.11 (2nd).
Home Runs per Game: 1.85 (2nd). Standard Deviation in R/G: High (1.76).
|Rates Per Park, 2010-12|
Launching Pad: High Desert, 3.10 HR/G (No. 1)
Graveyard: Modesto, 1.03 HR/G (No. 101)
Hit Parade: High Desert, 23.39 H/G (No. 1)
Pitcher's Park: San Jose, 9.28 R/G (No. 67)
Lancaster GM Derek Sharp describes the factors that make Clear Channel Stadium one of the minors' most hitter-friendly venues:
"We're at a higher altitude, for starters, but also the wind blows from west to east here, and it's always blowing out of the stadium, normally to right field. I've seen some crazy batting practices here in 30 mph wind. In April and May it can be cold here because we're in the desert, but it's almost always windy (as high as 35-40 mph). In the summer, even if it's not windy, we have a constant dry heat during the day that helps the ball carry.
"The (Cal League) Northern Division is a completely different atmosphere from here. There's more humidity up in north, plus they have more rain—it very seldom rains here."
IN FOCUS: Banner Island Ballpark, Stockton, Calif.
Stockton GM Luke Reiff:
"First of all, there is often a brisk breeze that is almost always directed out to left field. Secondly, there are two short porches. The left-field foul pole is just 300 feet from home plate; however, the distance increases at a sharp angle into fair play, and the wall at that point is 13 feet high. Additionally, there is also a short porch in right field to accommodate the "back porch" seating area. The right-field foul pole distance is 326 and right center is 389. This porch area extends about 15 feet into the field of play."
IN FOCUS: Sam Lynn Ballpark, Bakersfield, Calif.
Bakersfield director of broadcasting Dan Besbris:
"Our yard is homer-happy due to size. We simply play in a very small facility. The center-field wall is just 354 feet from home plate, which if memory serves makes us the shortest center field in affiliated ball. (Note: Beloit, Everett and Montgomery are next with listed center-field distances of 380 feet.) In addition, while most of the outfield wall is 14 feet high (a small attempt to cut down the number of home runs), there is a recessed catwalk that extends approximately 120 feet from right-center to a an area about 60-80 feet inside the foul pole in the right-field corner. Across this area, the wall is only eight feet high, which allows line drives to leave the park for homers, too. A small breeze coming in from the river beyond the outfield fence is about the only thing that keeps us from moving up the home-run list."
Carolina League (High Class A)
Runs per Game: 8.92 (7th out of 10). Hits per Game: 17.13 (7th).
Home Runs per Game: 1.36 (6th). Standard Deviation in R/G: Low (0.77).
|Rates Per Park, 2010-12|
|* 2010-11 in Southern League; park factor 2012 only|
Note: The Indians shifted their Carolina League affiliate from Kinston, N.C., to Zebulon, N.C., for the 2012 season.
Launching Pad: Frederick, 1.85 HR/G (No. 25)
Graveyard: Wilmington, 0.89 HR/G (No. 111)
Hit Parade: Winston-Salem, 18.36 H/G (No. 23)
Pitcher's Park: Wilmington, 7.73 R/G (No. 5)
Runs per Game: 8.58 (10th out of 10). Hits per Game: 17.03 (9th).
Home Runs per Game: 1.13 (10th). Standard Deviation in R/G: Low (0.75).
|Rates Per Park, 2010-12|
Launching Pad: Dunedin, 1.52 HR/G (No. 54)
Graveyard: Jupiter, 0.73 HR/G (No. 118)
Hit Parade: St. Lucie, 17.99 H/G (No. 31)
Pitcher's Park: Palm Beach, 7.50 R/G (No. 2)
Runs per Game: 9.13 (5th out of 10). Hits per Game: 16.96 (10th).
Home Runs per Game: 1.24 (9th). Standard Deviation in R/G: Lowest (0.48).
|Rates Per Park, 2010-12|
Launching Pad: Lake County, 1.62 HR/G (No. 47)
Graveyard: West Michigan, 0.87 HR/G (No. 113)
Hit Parade: Lansing, 18.06 H/G (No. 29)
Pitcher's Park: Bowling Green, 8.42 R/G (No. 23)
West Michigan vice president Jim Jarecki:
"We have a symmetrical ballpark with deep power alleys (385 feet), though it's 317 to left and 327 to right. We have northeast winds that tend to die after 7 p.m. game time. BP is windy, but come game time it dies down. The Whitecaps pitchers and pitching coach love it here."
South Atlantic League (Low Class A)
Runs per Game: 9.34 (3rd out of 10). Hits per Game: 17.32 (5th).
Home Runs per Game: 1.29 (8th). Standard Deviation in R/G: Moderate (1.21).
|Rates Per Park, 2010-12|
Launching Pad: Greensboro, 2.06 HR/G (No. 11)
Graveyard: Savannah, 0.63 HR/G (No. 120)
Hit Parade: Asheville, 20.04 H/G (No. 9)
Pitcher's Park: Savannah, 7.00 R/G (No. 1)
IN FOCUS: Grayson Stadium, Savannah, Ga.
Grayson is the most pitcher-friendly park in the minors, thanks to a variety of factors that team president John Katz explains:
"We've always been known as a pitcher's park. Our current dimensions are 322 feet to left field, 400 to center and 310 to right. We have a six-foot wall in left, but the remainder of the ballpark has a 16-foot wall, with the exception of the area beneath the video board which is a 'mere' 14 feet high. The left-field corner juts out deep to create an enormous alley to left-center, even with the lower wall. That 16-foot wall keeps a lot of balls in play.
"Parks in the South, with limited exceptions, are the least hitter-friendly. The sea breeze coming off the Atlantic plays a factor, along with the heavy, humid air. With 21 years in the game and having worked in Arizona, California, North Carolina, Virginia and Georgia, the climate plays a large role in parks being pitcher- or hitter-friendly. Sure, dimensions play a role, as does the quality of pitchers and hitters, but generally more humidity equals less home runs."
IN FOCUS: NewBridge Bank Park, Greensboro, N.C.
Greensboro president and GM Donald Moore:
"Our park has relatively short dimensions: 315 feet down the left-field line, 312 down the right-field line, about 360 to the power alleys and 400 to center. In addition to that, the typical prevailing winds blow from home plate to center field. Add all of that together with the fact that Low-A pitchers are learning to keep the ball down in the zone and you get a ballpark that will produce a lot of home runs."
IN FOCUS: FirstEnergy Park, Lakewood, N.J.
Member of Lakewood front office:
"We're only five miles from the ocean and frequently get a breeze blow in from the water. The moist air from off the ocean is thicker and kills fly balls. Plus, the fences are 12 feet high all the way around except in left-center (picnic area) and just to the right of dead center (tiki bar), where the fence is 20 feet high.
"The power alleys seem to jut out pretty quickly too, so right-center is a tough shot for left-handed hitters and straight left-center has the big wall for the right-handed hitters."