A New Way To Think About Ballpark Factors

Using 20-80 Scale Illustrates Park Effects

Update: The “grades” were calculated in a less-accurate manner when this piece was first published (May 1).

In the tables that follow, you will find traditional ballpark factors for runs scored per game* (Runs), home runs per game (HR) and batting average on balls in play (BABIP) for all 30 major league parks, plus the 160 minor league parks from Triple-A down to the traveling Rookie leagues.**

Following the traditional park factors are park “grades” for runs, homers and BABIP on the 20-80 scouting scale.

As an example, Denver’s Coors Field last year had a park factor of 130. This means that 30 percent more runs were scored in Rockies home games than in Rockies road games. Comparing that 130 park factor with the National League average (100) and dividing by the league’s standard deviation (12) yields a Z-score. That Z-score can then be mapped to the 20-80 scouting scale, where 50 is average, 60 is one standard deviation above average, 40 is one standard deviation below average, etc. I used five-point intervals for my scale. In scouting parlance, any number ending in a “5” is a half grade.

Using this Z-score method, we can estimate how each park impacts players. Going back to the Rockies example, Coors Field significantly impacts players who suit up there because the park receives “grades” of 75 for runs scored, 60 for home runs and 70 for batting average on balls in play.


AMERICAN LEAGUE
Team Affiliation
Runs HR
BABIP R Grade
HR Grade
BIP Grade
Baltimore Orioles 98 104 98 50 50 45
Boston Red Sox 117 104 110 65 50 65
Chicago White Sox 96 114 98 45 60 45
Cleveland Indians 120 116 109 65 60 65
Detroit Tigers 104 116 97 55 60 45
Houston Astros 81 82 97 35 40 45
Kansas City Royals 112 75 106 60 35 60
Los Angeles Angels 91 106 94 45 55 40
Minnesota Twins 102 99 100 50 50 50
New York Yankees 104 138 96 55 70 45
Oakland Athletics 86 75 95 40 35 40
Seattle Mariners 94 116 96 45 60 40
Tampa Bay Rays 89 88 95 40 45 40
Texas Rangers 114 104 109 60 50 65
Toronto Blue Jays 114 100 107 60 50 60

Hitter’s Haven

Cleveland | 65 runs • 60 home runs • 65 BABIP

Pitcher’s Paradise

Oakland | 40 runs • 35 home runs • 40 BABIP


NATIONAL LEAGUE
Team Affiliation
Runs HR
BABIP R Grade
HR Grade
BIP Grade
Arizona D-backs 117 123 108 65 65 60
Atlanta* Braves 104 75 103 55 35 55
Chicago Cubs 89 83 97 40 40 45
Cincinnati Reds 99 118 96 50 60 45
Colorado Rockies 130 120 113 75 60 70
Los Angeles Dodgers 86 97 97 40 50 45
Miami Marlins 87 83 92 40 40 40
Milwaukee Brewers 98 113 97 50 55 45
New York Mets 99 109 91 50 55 35
Philadelphia Phillies 84 115 93 35 60 40
Pittsburgh Pirates 103 82 104 50 40 55
San Diego Padres 98 93 100 50 45 50
San Francisco Giants 101 70 111 50 35 65
St. Louis Cardinals 94 91 97 45 45 45
Washington Nationals 95 102 96 45 50 45
* The Braves moved into SunTrust Park in 2017

Hitter’s Haven

Colorado | 75 runs • 60 home runs • 70 BABIP

Pitcher’s Paradise

Miami | 40 runs • 40 home runs • 40 BABIP


INTERNATIONAL LEAGUE (TRIPLE-A)
Team Affiliation
Runs HR
BABIP R Grade
HR Grade
BIP Grade
Buffalo Blue Jays 103 95 97 55 50 45
Charlotte White Sox 108 135 104 60 60 60
Columbus Indians 120 164 103 70 75 60
Durham Rays 106 124 102 55 60 55
Gwinnett Braves 100 104 101 50 50 55
Indianapolis Pirates 78 65 101 30 40 55
Lehigh Valley Phillies 107 97 103 55 50 60
Louisville Reds 98 110 96 50 55 40
Norfolk Orioles 95 68 97 45 40 45
Pawtucket Red Sox 97 127 90 45 60 25
Rochester Twins 103 78 100 55 40 50
Scranton/W-B Yankees 92 94 100 40 50 50
Syracuse Nationals 105 81 106 55 45 65
Toledo Tigers 92 83 100 40 45 50

Hitter’s Haven

Columbus | 70 runs • 75 home runs • 60 BABIP

Pitcher’s Paradise

Norfolk | 45 runs • 40 home runs • 45 BABIP


PACIFIC COAST LEAGUE (TRIPLE-A)
Team Affiliation
Runs HR
BABIP R Grade
HR Grade
BIP Grade
Albuquerque Rockies 132 134 110 65 65 60
Colorado Springs Brewers 147 89 125 70 45 75
El Paso Padres 111 125 104 55 60 55
Fresno Astros 101 102 96 50 50 45
Iowa Cubs 94 85 97 45 45 45
Las Vegas Mets 120 121 108 60 60 55
Memphis Cardinals 81 89 90 40 45 40
Nashville Athletics 79 64 93 40 35 45
New Orleans Marlins 78 96 89 40 50 40
Oklahoma City Dodgers 105 93 103 50 45 55
Omaha Royals 107 146 100 55 70 50
Reno D-backs 123 100 109 60 50 60
Round Rock Rangers 76 79 88 40 40 40
Sacramento Giants 77 95 90 40 50 40
Salt Lake Angels 107 112 110 55 55 60
Tacoma Mariners 78 89 89 40 45 40

Hitter’s Haven

Albuquerque | 65 runs • 65 home runs • 60 BABIP

Pitcher’s Paradise

Nashville | 40 runs • 35 home runs • 45 BABIP


EASTERN LEAGUE (DOUBLE-A)
Team Affiliation
Runs HR
BABIP R Grade
HR Grade
BIP Grade
Akron Indians 98 93 100 50 45 50
Altoona Pirates 109 79 107 60 40 65
Binghamton Mets 94 94 100 45 45 50
Bowie Orioles 107 126 100 55 60 50
Erie Tigers 93 88 103 40 45 55
Harrisburg Nationals 105 130 98 55 60 45
Hartford* Rockies 87 84 95 35 45 40
New Hampshire Blue Jays 110 104 107 60 50 65
Portland Red Sox 113 85 107 65 45 65
Reading Phillies 108 153 96 60 70 40
Richmond Giants 88 65 92 35 35 35
Trenton Yankees 89 96 97 40 50 45
* Hartford moved into Dunkin’ Donuts Park in 2017

Hitter’s Haven

New Hampshire | 60 runs • 50 home runs • 65 BABIP

Pitcher’s Paradise

Richmond | 35 runs • 35 home runs • 35 BABIP


SOUTHERN LEAGUE (DOUBLE-A)
Team Affiliation
Runs HR
BABIP R Grade
HR Grade
BIP Grade
Biloxi Brewers 96 119 96 45 60 40
Birmingham White Sox 94 88 96 45 45 40
Chattanooga Twins 119 137 104 70 65 55
Jackson D-backs 98 83 99 50 45 45
Jacksonville Marlins 99 120 97 50 60 45
Mississippi Braves 90 67 104 40 35 60
Mobile Angels 106 90 111 55 45 70
Montgomery Rays 108 100 103 60 50 55
Pensacola Reds 94 82 97 45 40 45
Tennessee Cubs 97 123 96 45 60 40

Hitter’s Haven

Chattanooga | 70 runs • 65 home runs • 55 BABIP

Pitcher’s Paradise

Pensacola | 45 runs • 40 home runs • 45 BABIP


TEXAS LEAGUE (DOUBLE-A)
Team Affiliation
Runs HR
BABIP R Grade
HR Grade
BIP Grade
Arkansas Mariners 82 56 102 40 40 50
Corpus Christi Astros 102 145 94 50 60 45
Frisco Rangers 121 116 112 65 55 65
Midland Athletics 115 78 106 60 45 60
NW Arkansas Royals 103 86 107 50 45 60
San Antonio Padres 77 64 92 35 40 40
Springfield Cardinals 106 168 92 55 65 40
Tulsa Dodgers 99 113 97 50 55 45

Hitter’s Haven

Frisco | 65 runs • 55 home runs • 65 BABIP

Pitcher’s Paradise

San Antonio | 35 runs • 40 home runs • 40 BABIP


CALIFORNIA LEAGUE (HIGH CLASS A)
Team Affiliation
Runs HR
BABIP R Grade
HR Grade
BIP Grade
Bakersfield* 106 141 107 55 60 65
High Desert* 131 152 102 65 60 55
Inland Empire Angels 84 64 96 40 40 40
Lake Elsinore Padres 88 67 99 45 40 45
Lancaster Rockies 134 171 109 70 65 70
Modesto Mariners 82 47 98 40 40 45
R. Cucamonga Dodgers 103 88 100 50 45 50
San Jose Giants 84 70 95 40 45 40
Stockton Athletics 89 108 96 45 50 40
Visalia D-backs 103 121 100 50 55 50
* Franchise realigned with Carolina League in 2017

Hitter’s Haven

Lancaster | 70 runs • 65 home runs • 70 BABIP

Pitcher’s Paradise

Inland Empire | 40 runs • 40 home runs • 40 BABIP


CAROLINA LEAGUE (HIGH CLASS A)
Team Affiliation
Runs HR
BABIP R Grade
HR Grade
BIP Grade
Carolina Brewers 79 93 96 35 50 45
Frederick Orioles 124 196 107 70 75 60
Lynchburg Indians 105 82 104 55 45 55
Myrtle Beach Cubs 96 109 94 45 50 40
Potomac Nationals 89 92 91 40 50 35
Salem Red Sox 106 53 108 55 40 65
Wilmington Royals 103 97 104 55 50 55
Winston-Salem White Sox 101 94 98 50 50 45
League added North Carolina franchises in Buies Creek (Astros) and Kinston (Rangers) in 2017

Hitter’s Haven

Frederick | 70 runs • 75 home runs • 60 BABIP

Pitcher’s Paradise

Potomac | 40 runs • 50 home runs • 35 BABIP


FLORIDA STATE LEAGUE (HIGH CLASS A)
Team Affiliation
Runs HR
BABIP R Grade
HR Grade
BIP Grade
Bradenton Pirates 100 98 101 50 50 50
Brevard County* Braves 94 88 103 40 45 60
Charlotte Rays 106 107 103 55 50 60
Clearwater Phillies 91 102 93 40 50 30
Daytona Reds 118 123 105 70 55 65
Dunedin Blue Jays 108 99 104 60 50 60
Fort Myers Twins 97 100 98 45 50 45
Jupiter Marlins 89 58 99 35 35 45
Lakeland Tigers 99 174 95 50 75 35
Palm Beach Cardinals 94 47 100 40 35 50
St. Lucie Mets 103 105 100 55 50 50
Tampa Yankees 100 80 100 50 45 50
* Franchise relocated to Kissimmee, Fla., to become Florida Fire Frogs in 2017

Hitter’s Haven

Daytona | 70 runs • 55 home runs • 65 BABIP

Pitcher’s Paradise

Jupiter/Palm Beach | 40 runs • 35 home runs • 50 BABIP


MIDWEST LEAGUE (LOW CLASS A)
Team Affiliation
Runs HR
BABIP R Grade
HR Grade
BIP Grade
Beloit Athletics 103 89 101 55 45 55
Bowling Green Rays 91 143 94 40 65 35
Burlington Angels 113 145 96 65 65 40
Cedar Rapids Twins 107 119 99 60 55 50
Clinton Mariners 90 87 96 40 45 40
Dayton Reds 108 120 106 60 60 65
Fort Wayne Padres 108 59 107 60 35 65
Great Lakes Dodgers 86 85 96 35 45 40
Kane County D-backs 94 72 100 45 40 50
Lake County Indians 103 127 101 55 60 50
Lansing Blue Jays 110 96 104 60 50 60
Peoria Cardinals 84 87 95 30 45 35
Quad Cities Astros 105 92 101 55 45 55
South Bend Cubs 97 112 99 45 55 45
West Michigan Tigers 98 62 103 50 35 60
Wisconsin Brewers 109 131 103 60 60 60

Hitter’s Haven

Dayton | 60 runs • 60 home runs • 65 BABIP

Pitcher’s Paradise

Peoria | 30 runs • 45 home runs • 35 BABIP


SOUTH ATLANTIC LEAGUE (LOW CLASS A)
Team Affiliation
Runs HR
BABIP R Grade
HR Grade
BIP Grade
Asheville Rockies 141 161 116 75 65 75
Augusta Giants 88 55 103 40 40 55
Charleston Yankees 84 52 99 40 40 50
Columbia Mets 89 90 93 45 50 40
Delmarva Orioles 99 70 100 50 45 50
Greensboro Marlins 104 206 97 55 75 45
Greenville Red Sox 100 106 101 50 50 50
Hagerstown Nationals 95 126 92 45 55 35
Hickory Rangers 94 116 98 45 55 45
Kannapolis White Sox 98 75 104 50 45 55
Lakewood Phillies 87 61 93 40 40 40
Lexington Royals 104 153 96 55 60 45
Rome Braves 120 71 105 65 45 60
West Virginia Pirates 102 116 102 50 55 55

Hitter’s Haven

Asheville | 75 runs • 65 home runs • 75 BABIP

Pitcher’s Paradise

Lakewood | 40 runs • 40 home runs • 40 BABIP


NEW YORK-PENN LEAGUE (SHORT-SEASON)
Team Affiliation
Runs HR
BABIP R Grade
HR Grade
BIP Grade
Aberdeen Orioles 103 99 101 50 50 50
Auburn Nationals 84 92 89 40 45 35
Batavia Marlins 89 69 98 45 35 45
Brooklyn Mets 80 66 101 35 35 50
Connecticut Tigers 82 56 93 40 30 40
Hudson Valley Rays 96 74 88 45 40 35
Lowell Red Sox 128 133 110 70 65 65
Mahoning Valley Indians 114 99 106 60 50 60
State College Cardinals 118 107 111 60 55 65
Staten Island Yankees 106 106 106 55 50 60
Tri-City Astros 115 128 108 60 60 60
Vermont Athletics 92 123 90 45 60 40
West Virginia Pirates 100 108 105 50 55 55
Williamsport Phillies 97 121 95 50 60 45

Hitter’s Haven

Lowell | 70 runs • 65 home runs • 65 BABIP

Pitcher’s Paradise

Connecticut | 40 runs • 30 home runs • 40 BABIP


NORTHWEST LEAGUE (SHORT-SEASON)
Team Affiliation
Runs HR
BABIP R Grade
HR Grade
BIP Grade
Boise Rockies 116 90 111 60 50 65
Eugene Cubs 71 59 90 35 40 40
Everett Mariners 120 182 106 60 65 60
Hillsboro D-backs 84 64 93 40 45 40
Salem-Keizer Giants 129 162 110 65 60 60
Spokane Rangers 102 134 98 50 55 50
Tri-City Padres 83 27 96 40 35 45
Vancouver Blue Jays 96 77 93 50 45 40

Hitter’s Haven

Everett | 60 runs • 65 home runs • 60 BABIP

Pitcher’s Paradise

Eugene | 35 runs • 40 home runs • 40 BABIP


APPALACHIAN LEAGUE (ROOKIE)
Team Affiliation
Runs HR
BABIP R Grade
HR Grade
BIP Grade
Bluefield Blue Jays 111 127 101 60 60 50
Bristol Pirates 92 109 91 45 55 35
Burlington Royals 94 124 94 45 60 40
Danville Braves 91 62 99 45 35 50
Elizabethton Twins 114 119 109 60 55 65
Greeneville Astros 99 94 95 50 50 40
Johnson City Cardinals 97 69 101 45 40 50
Kingsport Mets 88 97 99 40 50 50
Princeton Rays 126 144 106 70 65 60
Pulaski Yankees 94 62 108 45 35 65

Hitter’s Haven

Princeton | 70 runs • 65 home runs • 60 BABIP

Pitcher’s Paradise

Danville | 45 runs • 35 home runs • 50 BABIP


PIONEER LEAGUE (ROOKIE)
Team Affiliation
Runs HR
BABIP R Grade
HR Grade
BIP Grade
Billings Reds 104 105 98 55 55 45
Grand Junction Rockies 98 107 102 50 55 55
Great Falls White Sox 90 86 98 40 40 45
Helena Brewers 95 130 96 45 65 40
Idaho Falls Royals 121 82 110 70 40 70
Missoula D-backs 106 92 102 55 45 55
Ogden Dodgers 83 86 93 35 40 35
Orem Angels 104 124 101 55 65 50

Hitter’s Haven

Orem | 55 runs • 65 home runs • 50 BABIP

Pitcher’s Paradise

Ogden | 35 runs • 40 home runs • 35 BABIP


* In this case, the phrase “per game” actually refers to the rate per 76 plate appearances, which is the number of batters who come to the plate in a typical nine-inning game. Measuring park effects per PA (rather than per game) is more accurate because of seven-inning doubleheaders in the minors, extra-inning games and also games that don’t require a bottom of the ninth inning.

** To convert park factors to park multipliers that can be applied to individual players, use the following formula: (Park factor + 100) / 2 / 100. This halves the impact of each player’s home park to reflect the fact that he plays only half his games there.

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