How often are baseball spectators injured during game play?

Tonya Carpenter was injured by a broken bat at a Red Sox game against the Athletics.Barry Chin/Globe Staff

Ballparks across Major League Baseball, including Fenway Park, offer game-watchers close-up views of the action with unobstructed seats within 90 feet of home plate.

But these types of seats increase the risk of a spectator being injured by a batted ball or a broken bat. And it happens regularly — at Fenway, a spectator is hurt by a stray ball or bat once every three or four games, according to figures from a 2000 lawsuit against the Red Sox.

Most of the injuries are fairly minor, but some, including the serious injury to Tonya Carpenter by a shattered baseball bat at Fenway Park on Friday, can lead to hospitalization.

How often are baseball spectators injured during game play?

An average of 30 balls per game enter the stands at Fenway Park, according to foul ball statistician Edwin Comber.

Of that average, about half are hit and half are thrown by the bat boys, said Comber.

Across Major League Baseball, about 73 percent of foul balls go into the stands, said Comber.

While spectators may look forward to catching a foul ball, each one can result in potential injury, as can other items from the field, like the pieces of broken bat that hit Carpenter.

A 2014 Bloomberg analysis of foul ball-related injuries predicted that roughly 1,750 fans a year are injured due to batted balls at all of the Major League Baseball stadiums.

In fact, the number of spectators hurt by batted balls exceeded the number of batters hit by pitches, Bloomberg found.

At Fenway, a 2000 lawsuit against the Red Sox showed that over five years during the 1990s, the number of injuries sustained by fans at Fenway Park ranged from 36 to 53 per season.

How serious are these injuries?

More often than not, injuries sustained by a ball or bat are minor, a bruised hand or bloodied lip, according to Bloomberg’s review.

But more serious injuries have occurred. In 2010, a 6-year-old girl hit by a foul ball at a Braves game needed surgery for a shattered skull. In 2008, a 7-year-old was sent to the hospital with brain swelling due to a foul ball in Chicago.

And sometimes, these injuries can be deadly. Robert M. Gorman, co-author of “Death at the Ballpark,” told the Globe that of the 54 people in Massachusetts who died at a ballpark since 1862, 15 were spectators.

Are these injuries more likely to occur at Fenway Park?

It’s hard to say. The closer fans are to the game play, the greater their risk of injury, Bloomberg found. But no one has surveyed how many unprotected seats are close to home plate at all of the MLB’s ballparks.

Newer parks tend to have more field-level seats, according to the Bloomberg report, with fans sitting 7 percent closer to fair territory than at older stadiums.

At the MLB’s oldest ballpark, new field seats built in 2002 allowed Fenway to boast more seats within 90 feet of home plate than a dozen other ballparks, according to a 2003 Globe analysis.

At Fenway, the closest unprotected seat was just shy of 54 feet away from the plate, a smaller distance than most of the other ballparks.

The Sox considered extending the net behind home plate, the Globe reported in 2003, but decided against it, citing that fans wanted unobstructed views. They did raise the wall in front of the dugout seats by 6 inches at that time.

Despite the danger of sitting so close to the action, demand for these unprotected field seats — and their pricetag — was high.