If the professional bowlers tour had been on network television in the mid-1950s, we would have seen something like this:

About 10 minutes after air time, the tour's leader, Cannonball Jones, saunters onto the alleys. He's wearing a white T-shirt with "Herman's Bakery" on the back. The shirt flaps over his belt. A pack of Luckies is rolled up in his sleeve. Cannonball scratches under his arm as he waits for his ball to come up. Now he eyes the pins. Ready, set . . . gutter ball! "And now, ladies and gentlemen," the announcer says, "we bring you a word from Herman's Bakery."

In case you haven't noticed, there have been some changes since the Professional Bowlers Association signed its first contract with ABC television 20 years ago.

For one thing, the tour leaders show up on time, which is 3:30 each Saturday afternoon. They now wear color-coordinated outfits designed by King Louie, Munsingwear and Angeltown, the better for their TV image. Before they make their strike or spare, they don't grind out cigarette butts on the scorer's table. And whatever their secret vices, they don't wear the names of bakeries, pizzerias or body repair shops on their shirts.

What's more, they no longer call an alley an alley or a gutter ball a gutter ball.

Praise the PBA Image Committee! These fellows have cleaned up their vocabulary.

Alleys now are "lanes" or "centers."

Bowling balls fall into "channels," not gutters.

You don't hear about "keglers" aiming for the 10-pin any more. And if a pro bowler should head into a "beer frame" nowadays, he would never admit it to announcer Chris Schenkel and a live television audience.

"Bowling always had that stigma of being an alley-cat sport," says Schenkel, who has been with the tour since its inception on TV. "It was associated with rundown pool rooms, and they were very often combined. It was a place in less permissive days that parents didn't want their kids to go to."

The imponderable question in bowling is whether the sport's latter-day, squeaky-clean image is responsible for its television success, or vice versa. The one certainty is that bowling, the longest-running series in sports TV after NCAA football and "Wide World of Sports," is a television phenomenon.

When the PBA's Fair Lanes Open is beamed nationwide from Hyattsville today (WJLA-TV-7 and WJZ-TV-13 at 3:30), it probably will beat the NCAA college basketball tournament (CBS) in the ratings. Amazing as it seems, each PBA tournament draws an average of 20 million viewers compared to about 15 million for regular-season college basketball.

Through nine telecasts this year, the tour has drawn a rating of 8.8, meaning that almost 9 percent of all television homes in the country are tuning in. College basketball has averaged 6.3 on NBC and 5.5 on CBS over the same period. Pro basketball (CBS) has graded out at 6.0.

And that's just basketball. The argument can be made that bowling helped drive hockey and tennis off the networks. It also mangles golf. While Cadillac pitches its ads to the country club crowd, Rolaids spells relief for the bowling folk. The ratings show there are lots of upset stomachs out there. Three years ago, poor little Middle America bowling beat the prestigious Masters in the ratings.

What's so special about guys in pastel shirts knocking down pieces of wood for entertainment?

One thing is the format, which helps make bowling and television a perfect marriage. Not surprisingly, it was designed by an ABC producer, Ned Steckel, in 1967. The idea is to keep the drama building during the 90-minute show, so that if old Cannonball throws a gutter ball--oops, channel ball!--in the last match, your heart will stop.

Here's how it works: about 160 bowlers go at it each week until the field is narrowed to five for Saturday's show. The finalists then meet head to head in single-elimination matches in the inverse order of how they finished. No. 5 meets No. 4, the winner meets No. 3, and so on.

Meanwhile, the No. 1 finisher is waiting nervously in the wings. He has to win only one match while Nos. 4 and 5 have to win four, but he often tightens up standing around. Real-life drama, Saturday afternoon. ABC's cameras show him or his girl friend biting their lips.

Bing Crosby once said he watched bowling because "it is the only sport on television requiring no mentality on the part of the viewer." He meant this not as a putdown, but as a simple statement of fact: you don't have to think to watch. Just sit back, relax and watch 'em smash them pins.

Schenkel agrees, adding that bowling's down-home, unpretentious nature helps account for its allure. Commentator Nelson Burton Jr. offers cornball homilies such as, "Trust is a must or your game is a bust." Meanwhile, Schenkel lets you know if the No. 4 guy's father is a doughnut maker or if the No. 3 guy's sister is a registered nurse.

Is it too much to say there's a kind of sporting populism at work here?

"We hit the cross-section of America," Schenkel says, "and that's what these bowlers are. It's like somebody picked them out of a cornfield in Iowa or out of a soybean patch or out of a truck stop . . .

"Some people like to look down on people who bowl, like they were the scum of the earth. It makes me sick. All these years I've had to absorb giggles. 'Where are you going?' 'Oh, I'm going off to do a professional bowlers telecast.' Then you hear the giggles. I just walk out of the room."

He should save himself the effort. Outside the cosmopolitan cities of the East (Channel 13 in Baltimore shows every PBA tournament; Channel 7 in Washington does not), these modern-day gutter ballers, alley cats, beer framers and keglers have just about inherited the earth.