In Baseball, what is the Green Monster?

The Green Monster is the iconic, towering left-field wall at Fenway Park, home of the Boston Red Sox. Standing at 37 feet tall, it's a formidable challenge for hitters and a beloved feature for fans. Its unique color and height have shaped countless game moments. What fascinating stories has this legendary wall witnessed? Join us to explore its historic impact on baseball.
Dan Cavallari
Dan Cavallari

The Green Monster is the nickname of the unusually high left-field wall at Fenway Park, the home of Major League Baseball's Boston Red Sox. At 37 feet, 2 inches (11.33 m) tall and painted green, the wall, which can be seen in the photo below, is considered to be the most unusual and recognizable feature in any major league ballpark. The wall's height helps compensate for its comparatively short distance from home plate and makes it more difficult for batters to hit home runs than if the wall was a more typical height, such as 8 or 10 feet (2.4 or 3.05 m). Officially, the distance from home plate to the wall is 310 feet (94.5 m) down the left-field line, although some estimates and unofficial measurements indicate that the distance is possibly as little as 304 feet (92.7 m).


Boston Red Sox fans take pride in Fenway being the home of the green monster.
Boston Red Sox fans take pride in Fenway being the home of the green monster.

Fenway Park, which is shown in the photo below, was built in 1911 and 1912 on a small, asymmetrical city block in the Fenway-Kenmore neighborhood of Boston, Massachusetts. The layout of the ballpark in this constrained space, with one outfield wall running along Lansdowne Street, meant that the distance down the left-field line had to be shorter than usual. There also was no room for grandstands beyond left field. To keep non-paying customers from watching games from the street, a 25-foot (7.6-m) wooden fence was constructed. In front of the fence was a 10-foot (3.05-m) grass embankment, which usually was in the field of play but sometimes was roped off to allow fans to sit there during games that drew large crowds.

Fenway Park, home of the Green Monster, was built in 1912 in Boston, Massachusetts.
Fenway Park, home of the Green Monster, was built in 1912 in Boston, Massachusetts.

In 1934, new Red Sox owner Tom Yawkey had the embankment and fence replaced by a wood and iron wall that was 37 feet, 2 inches (11.33 m) high and 231 feet (70.4 m) long. The wall was fortified with concrete on its lower portion, and the upper part was covered by sheets of tin. A mesh screen that was 23.5 feet (7.2 m) high was added to the top of the wall in 1936 to help prevent home run balls from smashing the windows of buildings on the other side of Lansdowne Street. Originally painted with advertisements, the wall was repainted green in 1947. This gave rise to the wall's nickname, as opposing pitchers began referring to this inviting target for batters as a "green monster."

The tin covering of the wall was frequently dented by batted balls and developed many "dead spots," off which the ball would not bounce as much or in the way that was expected. In 1976, the wall was rebuilt with a hard plastic covering, which provided truer bounces, and safety padding was added at the bottom to help protect outfielders who crashed into the wall. A few advertisements and logos began appearing on the wall again in 1998.


At the base of the wall is a manually operated scoreboard, which is shown in the photo below. Attendants who watch from inside the wall use number panels to display the inning-by-inning score and other details of the game as well as the scores of other major league games. The walls of the room inside the Green Monster have been autographed by many players and other celebrities over the years.

In 2003, the top of the wall underwent significant changes. The screen was taken down, and seating for 269 fans was added. These seats have been extremely popular with fans, many of whom consider them the best place from which to watch a game at Fenway Park.

A ladder that had been used by attendants to retrieve home run balls from atop the wall was no longer necessary after the screen was removed. The ladder was left in place, however, and has remained one of the wall's many quirks. Balls can bounce off the ladder at odd angles. If a batted ball hits the ladder below the top of the wall and bounces over the wall, it is ruled a ground-rule double and not a home run.

Effect on Players

The Green Monster adds a unique element to playing left field at Fenway Park. Outfielders must learn how to play caroms off the wall, although erratic bounces are less common than when it was covered by tin. Even if the ball is caught after hitting the wall, the batter is not out. Outfielders must try to judge where the ball will land after it hits the wall so that they can retrieve it as quickly as possible and throw it to an infielder. Some outfielders have become experts at catching balls of the wall and throwing out baserunners at second base.

From the batter's perspective, the short distance to Fenway Park's left-field wall provides its own opportunities. The wall is officially 310 feet (94.5 m) from the plate down the left-field line and angles outward to a distance of 379 feet (115.5 m) in left-center. In 1958, Major League Baseball passed a rule that new ballparks must be constructed with the outfield wall at least 325 feet (99.1 m) from home plate, although existing walls could remain at shorter distances. Most major league ballparks are at least 330 feet (100.6 m) down the line, so batters at Fenway Park often try to take advantage of its closer left-field wall.

Some batters will try to hit high fly balls toward left field in hopes of the balls going over the Green Monster for home runs. Others will try to bang line drives off the wall for doubles. Pitchers at Fenway Park typically try to throw lower pitches, especially to right-handed hitters, because higher pitches can be more easily hit into the air toward left field.

Fisk's Home Run

One of the most famous moments in Fenway Park history occurred during the 1975 World Series between the Red Sox and the Cincinnati Reds. In the bottom of the 12th inning of Game 6, the Red Sox's Carlton Fisk hit a game-winning home run off the foul pole above the Green Monster. The following video captures that moment, including Fisk famously jumping and waving his arms at the ball in the hope that it would stay fair as it flew over the wall.

Similar Walls

Many attempts have been made to simulate or duplicate the Green Monster in other ballparks, mostly minor league stadiums. Two of the Red Sox's minor league teams, the Portland Sea Dogs in Maine and the Greenville Drive in South Carolina, for example, each have similar left-field walls. These walls help give future Red Sox outfielders experience fielding balls that rebound off high left-field walls. Among the other minor league stadiums that have high left-field walls are those in York, Pennsylvania; and Asheville, North Carolina.

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Discussion Comments


It's amazing in this day and age of new is better that the Green Monster is still standing. Even old Yankee Stadium has been torn down.


At first glance, you might think the short distance to the Green Monster would help all Red Sox players have more home runs since they play half of their games in Fenway Park, but think again.

Jim Rice was a hard-hitting outfielder who played his entire career with the Red Sox. He hit slightly fewer than 400 home runs. If he had played with any other team, and not played so many games in Fenway, he probably would have hit 500 home runs.

Rice hit the ball hard and on a line so instead of landing in the bleachers, many of the balls he hit bounced off the Monster for doubles or singles instead of home runs.

Sporkasia - Have you been to game at Fenway Park? I have attended games at a number of Major League ballparks and none quite live up to Fenway. The Green Monster is a part of the draw, but it is that and more that makes Fenway unique.

For one thing, the fans are raised on Red Sox baseball, so it is a tradition passed from generation to generation. Fans expect a lot from the players who wear the Boston uniform, and they will support their team through good and bad times. Fans will also loudly voice their opinions (good and bad) about players and management.


I still remember the Carlton Fisk home run over the Monster in 1975. Actually, I was a kid at the time and had to go to bed before that game ended, but my father told me about it the next morning and I have seen the highlight too many times to keep count.

I have been a Red Sox fan ever since.

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    • Boston Red Sox fans take pride in Fenway being the home of the green monster.
      By: BU Interactive News
      Boston Red Sox fans take pride in Fenway being the home of the green monster.
    • Fenway Park, home of the Green Monster, was built in 1912 in Boston, Massachusetts.
      By: pavalena
      Fenway Park, home of the Green Monster, was built in 1912 in Boston, Massachusetts.