WASHINGTON (Reuters) - It always makes the video highlights: a batter hits a "walk-off" homer and his team mates race to home plate to greet him. As he rounds third base, he flips off his batting helmet and prepares for the jubilant back-slapping due to him as the game's hero.
He encounters far more than good-natured back-slapping, however, from a chaotic mob of celebrating team mates jumping up with their arms and hands flailing away at his back and shoulders.
In recent years, that flip of the helmet has become part of the walk-off home run drama. Rounding third, some players make a show of throwing off the helmet by casting it coolly aside or feigning to roll it like a bowling ball.
Most, however, just get rid of the helmet as a defensive measure to signal to exuberant team mates not to thump them on the head.
"When you reach home you're patted on the back and guys that can't reach your back are reaching across and hitting you in the head," said Philadelphia Phillies slugger Ryan Howard, who has hit three walk-off homers in his career.
"If you throw the helmet off, they're not going to hit you in the head...it eases cerebral damage."
Walk-off homers are so called because the players walk off the field when the batter reaches home because the game is over.
This Major League Baseball (MLB) season started with the Washington Nationals' Ryan Zimmerman clubbing a thrilling walk-off homer at the club's new ballpark on opening night to top the Atlanta Braves, flipping his helmet as he rounded third.
Since then, David Ortiz of the Boston Red Sox and the Detroit Tigers' Miguel Cabrera, Jay Bruce of the Cincinnati Reds and Carlos Quentin of the Chicago White Sox are among players to have hit walk-offs.
Their homers were hit on different nights, yet the same edited sequence made the video highlights: the swing of the bat, the flight of the ball into the stands and the runner flipping his helmet before jumping into a scrum of hysterical players waiting at home.
The Nationals' catcher Wil Nieves hit a walk-off homer to top the Chicago Cubs on April 25. Even though it was his first big-league home run, he knew enough to toss off his helmet.
"I saw Alex Rodriguez...and Bobby Abreu taking it off after walk-off hits and they didn't get hit as hard in the head," Nieves said, speaking of the two New York Yankees big names. "When I was coming home and I saw all the guys I thought, I'm not keeping it. So I threw it away.
"They still punch you in the ribs and do other stuff but won't hit you in the head as hard."
Nieves said players first saw the helmet-flip in the minor leagues. "I hit a walk-off double in the minors," he said. "It's the same thing, whether a base hit or homer, they run to you and hit you in the helmet and jump with you...
"It's exciting too, taking the helmet off and throwing it away."
The helmet flip is certainly not part of training drills, though it has become an antic that knowledgeable fans expect whenever a walk-off homer is hit.
No one is sure when the helmet-flipping trend began, just as it is not known when the term "walk-off" was first used to describe dramatic, game-winning homers.
"If you read an article in the 1980s, it said a homer was a game-ending homer... It probably wasn't until the late '90s and early 2000s when the statistic came into vogue," said John Labombarda of the Elias Sports Bureau, the baseball statistic-tabulating organization.
"Every baseball fan notices (the flipping of helmets) and knows the reason: the pounding on the helmet is worse than the pounding on the head."
You now hear of walk-off singles, doubles and triples. "Everything's a walk-off now," said Labombarda.
Phillies outfielder Geoff Jenkins said he got as excited as anyone when a team mate hit a walk-off homer. "I run on the field and go nuts on the guy, jump on him."
He has hit three walk-off homers during his career. Yet he also remembers when he was the recipient of a walk-off hit-by-a-pitch. He could not recall if he flipped his helmet, he said.
"It's like, what do you do? You take your base" and win the game.
Editing by Clare Fallon