Men's Senior Baseball League, where guys continue to play even into their 70s. (Kevin Richardson/Baltimore Sun video)

The ball leaps off the bat, kicks up dust and bounds toward right field, a sure hit.

Tom Coffin reckons not. The second baseman glides left, gloves the ball cleanly and throws the runner out. Coffin's teammates on the Colt .45s explode.

"Woo-hoo!"

"Way to go, Mr. Tom!"

"You showboat, you!"

Why the fuss? Coffin, a great-grandfather, is 73.

It's Sunday morning in Dundalk and, on the American Legion baseball field, geezers like Coffin are feeling their oats. Once a week, nearly 150 players — from middle-aged men who still cherish the game to 70-somethings who inspire the rest — compete in the 10-team Eastern Baltimore County Over 40 Baseball League. The melange of teachers, lawyers and truck drivers suit up in expansive double knits, swing bats with patriarchal gusto and swap good-natured banter as in days of yore.

They are not alone. In the Baltimore area, senior baseball leagues have also blossomed in Anne Arundel, Carroll, Harford and Howard counties. Nationally, two organizations — the Men's Senior Baseball League, with 45,000 players, and Roy Hobbs Baseball (8,000) — hold postseason tournaments with age-group divisions ranging from 18 to 75-and-over.

"Baseball does a great job of keeping guys fit and extending their lives," said Brian Sigler, national coordinator for the MSBL. "You hear the same chatter in a 65-and-over game — 'C'mon, kid, let's strike him out' — that you'd hear in high school.

"Guys still have that itch; they never want to give it up."

Men's softball, Sigler said, doesn't cut it.

"Our motto is, 'Don't go soft, play hardball.' You've got to be more in shape for this," he said. "And you don't walk away [from softball] feeling that you've really competed. Playing in shorts is just not the same."

'One more summer in the sun'

Some oldtimers, like Coffin, stray from baseball but return. A retired steelworker, he hadn't played in 50 years when he dug out his cleats in 2010 after signing up his grandson for Little League.

"My first game back, I pulled a hamstring and thought, 'Why am I doing this?'" said Coffin, who starred at Dundalk High in the 1950s. "I've got children older than a lot of these guys. But it gets better every year. My arm is still weak, but I stole a base. I hit a double.

"Now if I can just get my timing back, maybe I can put one over the fence."

Coffin plays alongside first baseman Rex Frost, 69.

"The right side of my infield may be 142 years old," said Brian Weir, the Colt .45s manager, who is 53, "but they know the fundamentals and they make the plays."

Frost bats cleanup and, on this day, hit two singles and knocked in a run in his team's victory. He's hitting .389 despite an aching back (spinal stenosis), for which he takes four anti-inflammatory drugs before each game.

"Am I nuts? Probably, but there's no place I'd rather be," said Frost, a retired psychiatrist who lives in Phoenix. "Six months ago, my doctor told me I was dying, that I had killed my kidneys taking so many pills and that I needed dialysis."