This blog was inspired by a class I took at UC Berkeley while I was in high school.
In my project, I looked at how certain ballparks favor certain hitting trends. To do this I used a dataset on dimensions of the different MLB ballparks, and overlayed it with hitting data from the 2023 season. I then looked at trends to see how certain aspects of ballparks affected the hitting trends of teams.
For ballpark dimensions I looked at:
- Distance to left field wall
- Distance to center field wall
- Distance to right field wall
- Minimum wall height
- Maximum wall height
- Average length of the field
As well as
- Elevation above sea level
- Average temperature of games
- Percentage of games played with a roof
- Percentage of games played during the day
For hitting stats I looked at:
- Singles
- Doubles
- Triples
- Home Runs
- Batting Average
- Double Plays
- % of Soft Hits (exit velocity < 95 mph)
- % of Hard Hits (exit velocity > 95 mph)
- % of Pulled Hits
- % of Pushed Hits
- % of Hits to Center Field
- Speed
Using the hitting data, I grouped players by team and calculated the average value for each statistic. I then simulated a permutation hypothesis test on each stat with the park dimensions, showing which relationships may have occurred by chance, and which were actually meaningful. I then calculated the correlation coefficient to see if there was a strong positive or negative association between the stat and the dimension.
In other words, I created a program to see if there was a relation between hitting statistics, and different MLB ballpark dimensions.
Trends Observed:
Please Note: These results show correlations, not cause-and-effect relationships. These are just my interpretations—not proof that the ballpark caused the result.
- As the percentage of games played under a roof increases, the average number of singles hit by the home team tends to increase
- Possible explanation: Enclosed stadiums trap air and moisture, making the air denser. This dense air reduces the flight distance of batted balls, which could lead to more hits falling for singles, rather than extra-base hits
- Teams that play more than 50% of their home games under a roof: Tampa Bay, Miami, Houston, Texas, and Arizona
- Same trend for amount of doubles hit
- As average temperature, elevation, and length of field increases, the average number of triples hit by the home team tends to increase
- Possible explanation: Hotter and higher places have less dense air meaning the ball can fly farther. Typically, when a team knows that they will have to deal with those conditions, they will make their outfields deeper, providing more space for balls to stay in play, and runners to leg out a triple.
- Teams in the hottest areas: Arizona, St. Louis, Atlanta
- Teams at the highest elevations: Colorado, Arizona, Atlanta
- Teams with the deepest outfields: Colorado, Arizona, Texas
- Looking at all of the factors together, the Diamondbacks appear to have the most triple-friendly ballpark
- As amount of games played during the day decreases, the amount of home runs hit by the home team increases
- Possible explanation: Most day games happen after a night game, so players who play in both games don’t get as much sleep for the day game. The Sun during daytime games can also cause glare or shadows, making it harder for batters to track the ball
- Teams that consistently have the most night games across the league: Dodgers, Angels, Marlins
- As percentage of games played under a roof increases and the percentage of games played during the day decreases, the average amount of double plays hit into by the home team increases
- Possible explanation: During the colder night, the air is denser, so pitches with downward movement are more likely to have that movement amplified. This means the contact point for batters is higher, leading to more ground balls. Most ballparks with a roof are climate controlled, meaning the air is cooler than the outside temperature during day game, leading to consistently denser air that reduces the air time of balls.
- Miami plays almost exclusively under a roof, and consistently schedule night games, so their ballpark appears to promote a lot of ground balls
- As average temperature goes decreases and as the length of a ballpark’s outfield decreases, the contact on batted balls by the home team appears to be softer
- Possible explanation: The lower the temperature, the denser the air, increasing the force of drag on the ball. In shorter fields, hitters adjust by focusing on hit placement and contact control rather than swinging for raw power
- Teams that play in the coolest climates: Mariners, Giants, Red Sox
- Teams that have the shortest outfields: Guardians, Phillies, Yankees
- As the length of a ballpark’s outfield increases, the contact on batted balls by the home team tend to harder (interesting we don’t see this trend with an increase in temperature)
- Possible explanation: Teams that play with longer outfields try to hit the ball as hard as they can to clear deep outfield fences
- Teams with the longest outfields: Colorado, Arizona, Texas
- As distance to the poles (both left and right field) decreases, then the amount of balls pulled by the home team increases
- Possible explanation: Knowing that its easier to hit the ball out in fields with closer walls, batters will try to hit the ball towards those areas maximize their chances of hitting a home run (right field is the pull side for lefties)
- The team with the closest foul poles to home plate is Boston
- As outfield length increases, then the amount of balls hit by the home team to center field increases
- Possible explanation: Batters will adjust to bigger outfields by hitting back up the middle towards the ballpark’s deepest areas, since pitchers try to avoid pull side home runs where the distance from home to the wall is shorter
- Teams with the biggest outfields: Tigers and Rockies
- As distance to the left field wall increases, the amount of pushed balls hit by the home team increases
- Possible explanation: Most hitters are right handed. Therefore, when it becomes harder to hit the ball out on their pull side, they will try to go opposite field
- Teams with the greatest distance from home plate to the left field wall: Cubs, Rockies, Tigers
- As average wall height increases, and the length of the outfield increases, the batting average of the home team tends to increase
- Possible explanation: As the wall height increases, it becomes harder to hit home runs, so batters may adjust from all or nothing power swings, to more contact-focused approaches where they can drive the ball into deeper, more open fields
- There is no team with this particular setup, but teams close to it include the Red Sox (due to the Green Monster and their huge right-center field), Tigers (huge overall outfield), and Cubs (above average brick and ivy walls)
- As the minimum height of walls increases, the amount of runs scored by the home team due to base running increases
- Possible explanation: Tall walls stop potential home runs from leaving the park. Balls that hit off the wall remain in play, forcing baserunners to run aggressively to score on doubles and triples.
- Teams with the highest minimum wall heights include the Cubs, Braves, Royals, Guardians, Rays and Marlins
*Note: Hitting data is from 2023. Ballpark data should be accurate, except for the Athletics, who recently temporarily relocated to Sacramento in 2025
Biggest Takeaways:
- Looking at all of the relationships I saw:
- The most hitter friendly ballpark appears to be Arizona’s Chase Field
- San Diego’s Petco Park was consistently on the lower end of these rankings, making it seem to be a more pitcher-friendly ballpark
- Important: This is just hitting data and ballpark dimensions. It does not take away individual hitter skill
Why is this important?
This data provides essential context to raw hitting metrics by explaining the underlying environmental conditions and ballpark mechanics that impact performance. These influence decisions during the draft, or help identify players with hidden value that may be caused by underlying environmental factors. Understanding these variables gives teams in edge in trade talks, and gives players things to consider when making free agency decisions.
This project forms the basis for many of the opinions and conclusions I make throughout this blog. Hopefully it gives some context for why I make certain claims—and proves I’m not just going on a crazy rant. Hope you enjoy my blog!
To see the actual project: