On August 17, 1920, Ray Chapman of the Cleveland Indians was struck on the head by a pitch thrown by Carl Mays of the New York Yankees. Chapman crumbled to the ground as Mays fielded the ricochet and threw to first.

Chapman seemed to come around for a bit, despite blood coming out of his ear, and was being helped off the field when he collapsed.

He died in a hospital about 12 hours later.

Nearly 87 years later, Chapman is still the only Major League Baseball player to have died from an injury suffered on the field during a game.

It feels, however, like baseball’s luck is about to run out. Especially considering how often pitchers are being hit by line drives these days.

Like, for example, pitcher Lance Lynn of the St. Louis Cardinals, who took a liner off his head this week … scaring everyone who saw it.

Lynn apparently was not seriously hurt. He not only got up, he talked his manager and the trainer into leaving him in the game. However, a goofy interview he gave after the game made a person wonder if Lynn were not a little addled.

Pitchers have been getting hit by batted balls a lot lately. A lot. And this in an era of what appear to be bigger and stronger players trying to kill the ball every time they swing. An age when the “exit velocity” of a batted ball is studied and celebrated.

What we know to be true is that no pitcher can throw as hard as a ball can be batted.

Robbie Ray of the Arizona Diamondbacks was beaned last month by a ball that reportedly was traveling 108 miles per hour. He suffered a concussion and took three staples in his head to close a wound. He has not yet returned to action.

In 2015, Archie Bradley of the Diamondbacks was hit in the face by a ball moving 115 mph. He posted a gruesome selfie from the hospital in which his face is decidedly lopsided by swelling.

The scariest incident of recent vintage was when Brandon McCarthy suffered a skull fracture in 2012 when hit by a batted ball, and needed two hours of surgery to relieve pressure on his brain.

And here is a six-minute compilation of players getting hit in the face/head, about evenly divided between pitchers and hitters.

The one baseball fatality (Chapman in 1920) was a batter, but that came before batters were required to wear helmets, and before dirty baseballs were immediately taken out of play, as they are now.

(Many believe Chapman never saw the scuffed and dirty ball that killed him.)

Batters still can be badly hurt by a pitched ball, but the helmet usually covers the temple — the thinnest part of the skull — and reduces the chances of mortal damage.

First basemen and third basemen, as well as the coaches at each base (who almost always are even closer to the plate than the fielders) also are at risk.

Pitchers, however, are worst off.

They stand only 60 feet, 6 inches from home plate, and less than that by the time they stride toward the catcher, and they are wearing no defensive gear at all.

The ball gets there in a hurry, and pitchers sometimes can’t even get their hands up in front of their face or head.

Those are the deeply alarming injuries.

In 2014, Alex Torres of the San Diego Padres became the first pitcher to wear a cap/hat with protective shielding built in. He said he wanted to protect himself, after seeing a former teammate, Alex Cobb, drilled in the head the previous season.

Baseball gets semi-serious about this, now and then, and before the 2016 season put up a post that shows what pitchers’ protection might look like. It is not as bulky as the device/cap worn by Torres.

Now, comes the time for making protective gear mandatory for pitchers. No more talk about being distracted or unable to “flow a pitch” to the plate.

If nothing is done, someone is going to get killed. We all know it in our gut.

Only by preventative action can MLB hope to leave the tragedy of Ray Chapman as a one-off event.