'Tis the season for lots of things, but not baseball. That is, unless you are a Martz Insurance Christain.

The bizarre, indefatigable Martz sandlot nine plays baseball every day of the winter, come snow, sleet or Santa Claus.

On a recent December Sunday morning, the sky glistened with a winter brilliance and by nine o'clock the mercury had risen to a frosty 20 degrees.

In other words, it was a perfect day for a doubleheader.

On a raw, frozen playground near the Washington Cathedral, the Martz Christians, as they have been called for short since Edsel Martz, their insurance-salesman founder, was "born again," congregated for their ritual sandlot service.

The opposition was an almost equally hardly band of diamond zealots known simply as Battista.

Battista is the other team in Washington, and perhaps the world, which claims to practice every winter day.

"I'm suspicious," says Martz and generously leaves it at that.

The two-dozen muffled and parkaed players, looking like a polar expedition, quickly began setting about their wintry baseball preparations.

The 17-year-old Martz shortstop tosted the rock-hard, grassless infield earth with his spikes, then shook his head. Might as well wear track shoes to ice skate. He would have to play shortshop in combat boots.

The teen-age catcher stuffed half of a pack of Red Man tobacco into his jaw, then patiently adjusted his seven layers of clothing so that he could squat without any loud ripping noises.

"Shoot it to me, doctor," he crowed to his pitcher, sounding like a defiant young baseball chanticleer in deepest winter.

A bonfire was rapidly built and the players gathered around it, each warming the frigid handle of his aluminum bat over the flames. It looked like a surrealist marshmallow roast.

"Don't get those handles too hot," warned one player, "or you won't be able to hold 'em, even with your gloves on."

Words of chilly commiseration ewer exchanged.

"Don't worry. Once you get numb, it's O.K. . . ."

"Use your mind. Get over top of the cold. Ignore it . . ."

"Hey, look on the bright side. What a great day to hit frozen ropes . . ."

Actually, subfreezing temporatures are the smallest of the hindrances to the Winter Game.

In a mere inch or two of snow, or a minor sleet blizzard, the game goes on.

After a major snowstorm, however, a bit of improvisation is nescessary.

"We roll the snow into a huge ball, starting behind home plate and working it out beyond the mound," explained one player. 'You end up with a great snowman and 60 feet of cleared ground."

The patron saint of this voluntary form on baseball martyrdom, Martz, stands behind the backstop, swathed from head to toe. He looks very warm.

"I'm thinking of all the kids in California growing up like Ted Williams did, playing ball 365 days a year, snapped Martz. "No wonder they dominated the game these days.

"This," he said, nodding at the makeshift diamond, besmirched by the linings of a soccer field, "is the only way a Washington kid who loves baseball can make up for not living in the dadgone sun belt."

The whole geographical and meteorological injustice of it annoys Martz so much that he has stretched his principles.

His team practices two hours every weekday evening at Williamsburg Junior High in Arlington, then plays a Saturday doubleheader. But that traditional Sunday Martz doubleheader has caused the ex-Marine drill sergeant some anguish since he was born again.

"I thought about it a long time," he said. "But you know God made man for the Sabbath, not the other way around . . . And I'm not making any money out of this.

"Anyway," he confided, "I'm a Catholic and we have bingo on Sundays, so I figure the Catholics have researched it."

To be on the safe side Martz keeps a transistor radio in the pocket of his greatcoat. The silence of early Sunday morning is broken only by the hiss of the dun-colored Lall speeding to the plate, the sharp clank of aluminum meeting cold horsehide and a steady undercurrent of organ music and "Amens" coming from the gospel service in Martz pocket.

Nevertheless, the only common conviction among Martz players is that they are basebell fundamentalists.

"Edsel has Protestants, Catholics and Jews on this team," said Phil Yeager, father of southpaw Warren (Spahnie) Yeager. "The only thing they gotta believe in is baseball."

And they do. When the grizzled coach tells them, "Rogers Hornsby rapped his shin with a bat before he went to the plate to get himself in the right frame of mind," their eyes get big.

No two players on the field - ranging from age 13 up to early 20s - are there for the same reasons.

At least two, Ben Bregman and Scott Wolfe, are legitimate prospects, either for sun belt colleges or even the big league draft.

"I've played over 200 games since last spring," said Bregman, a senior at Walter Johnson High. "Work pays off. This is the biggest year of my life. I'm not gonna blow it.

"I've got six months to determine if I'm going to be working on a construction site or going to college on a baseball scholarship."

Playing for Martz is only a fraction of Bregman's baseball devotion.

"I've rented a barn in Germantown, about 50 miles round trip from my house. I pay the farmer $25 a month," he said proudly. "I've got a Jugs (pitching) machine in there that will throw 100 miles an hour."

And of a winter's day Bregman will drive to his sequesterde barn and hit for hours in the cold, wearing heavy work gloves.

"But I'm not tellin' anybody else where it is," said Bregman, "I don't want 'em horning in."

Bregman need only glance down the Martz bench to see the baseball limbo he wants to avoid. There sits Terry Brooks, 20, of Ellicott City, an adolescent prospect turning into an adult suspect before his own worried eyes.

"It's getting late for me." said Brooks, who drives nearly 100 miles for Martz games. "A coupla scouts got their eye on me, I think, but I gotta make my move.

"Hey, baseball is what I do. It's what I'm good at. I work in a warehouse in Baltimore, see, and I got these crates against one wall and I throw against 'em on my lunch hour. I've got four circles on them for the corners I want to pitch to.

"It's OK, I guess.But really, it's not too great, even if you got a warm warehouse like I do."

So Brooks, who has pitched semi-pro, was ecstatic to learn about the Martz fanatics.

"Baltimore . . . whatdays expect? We got nothing like this," said Brooks."It's too good to be true."

On this particular subfreezing day Brooks could not throw a ball 20 feet. "I wrenched my back yesterday when a trailer slipped. I could barely get out of bed this morning. But I figured if I came over here, maybe I could work the stiffness and pain out."

What's a hundred miles, anyway?

"I don't think you could get anybody to watch us from up on that hill and not have 'em say we're crazy," said Brooks. "Sure, it's a long trek to play a little ball, but it's there, you know what I mean, so you got to get it.

Mixed with these serious ballplayers are 16 and even 13-year-old. Most foresee high school semi-stardom and a college scholarship. They are at a stage of life where they are exhilarated by their own dedication, amazed at what they can achieve.

"I faced this real fast grownup pitcher one Sunday last spring and got a hit," bubbled Tom Rudden, who was in junior high school then. "And the next day at school I faced a 12-year-old and I couldn't hit him. Too slow."

"My mom still doesn't understand what I'm doing out here," said Spahnie Yeager, a junior at Woodson High, with a shake of the head.

But Yeager's father does. "Warren has picked off 58 runners this year." said the proud dad, leaning on the backstop. "Sometimes I think he'll walk a man just to pick him off."

The more outlandish their sacrifices seem, the prouder the boys of winter become.

"We started out with 14 teams playing fall baseball in Virginia," said John Burzynski of West Springfield High. "But one by one they've been dropping out."

Meanwhile, the Martz Christians are just building up to their winter highlight - a six-day trip to Florida for doubleheaders every day at the old New York Giant complex in Sanford. They leave Christmas Day.

Burzynski is up at 4 a.m. working his newspaper route to save money, then goes to school, practices in the afternoon, and finally studies at night until his eyes won't stay open. "Heck," he said, "I just sleep 14 hours a night on weekends to catch up."

The Martz players know that fingers are pointed at them, that some of their peers look at them with giggles of disbelief.

"They say, 'What are you doing? You'll ruin your arm. You'll get sick of baseball.'" said Yeager with a shrug. "But they play three months a year and I play 12. I figure I'm getting four seasons of experience to their one. In just the last year I've changed from a finesse pitcher to a power pitcher."

Mostly, the Martz maniacs are too busy figuring out how to beat the cold to worry about philosophical problems.

Gary Carlton of O'Connell High has put Ben Gay on his arm underneath his five sweatshirts. Now he is chewing the finger tips off the index and middle fingers of a rather expensive looking pair of heavy-duty winter gloves.

"Breaking in a new glove," he cracked. "Gotta be able to feel the seams on the ball to be able to throw a good curve in December."

Martz and Battista have been going at each other for more than five hours. They are in the 14th inning of the second game. The sun had just risen when they began. Now it is thinking seriously about going down.

Al Battista, 20, an American University student and JV coach at St. Albans School, was on the mound when the doubleheader began and he is still there 21 innings later. He only pitched seven innings the day before.

"He's no prospect," Martz said respectfully. "He knows he can't ruin his arm, 'cause he ain't got one. But he's a great kid. He refuses to come out. He's got guts."

Battista kept chucking screwy curves out of one the most unbelievable herky-jerky windups imaginable.

"Get two . . . bear down, extra innings . . . shoot it to me, doctor," went the chatter.

"Don't tell me about them old-time pitchers," said Martz. "Iron Joe McGinnity never pitched no 21 innings on a day like this."

The temperature, which almost reached freezing at the height of the second game, is going down again.

"Come on," Martz commanded his hitter, stamping a numb foot on the frozen tundra. "Get a hit off this bum."