For those who like to play little games, there is the test of memory sometimes known as today's trivia question. As a current for instance, who is the heavyweight champion of the world?

The answers to that one used to leap from the lips of generations of boxing fans reciting names like Jack Dempsey, or Tunney, Louis, Marciano, Liston, Frazier and Muhammed Ali. But now it takes some ruminating.

Give up? Leon Spinks. And never did a new and still reigning champ achieve relative obscurity with such rapidity. Five months after he astonished the world by smashing the braggart Muhammed Ali in 15 rounds at Las Vegas, Spinks gets rare mention in the public print. Meanwhile, Ali, the loser, is making headlines over much of the known world, fuzzing up the fact that Leon Spinks is the champion.

Spinks' public notices, meanwhile, have usually been limited to paragrah mentions of his regular and tiresome skirmished with nosy speed cops who also care inquiring about his driver's license, if any. There have been four of these instances.

In these encounters with the lawmen, Spinks' leadoff defense has been: "Don't you know who I am?" Mostly, the cops say they don't care and, worse for Spinks, some of the cads indicate they never heard of him.

It is a futile mismatch for public attention with Ali. Ali not only makes the black-tie-dinner circuit in Washington regularly, including at least three stops at the White House, but he popped up on the front pages again the other day by showing up in Moscow as the newborn friend of Leonid Brezhnev, who received him in the Kremlin with mutual hugs and kisses, to and fro.

In the dismayed eyes of President Carter, Secretary of State Vance and Security Council boss Brezinski, Ali was guilty of two things: bad timing and total ignorance of what is really going on in the Soviet Union. Sample statements: "All Brezhnev talked about was peace and humanity . . . In Moscow I didn't see one gun or one policeman." . . . "On Moscow's streets when I was running early in the morning I didn't have to worry about being mugged." . . .

So, take that America, and read all about Ali on the front pages.

This is too formidable for poor Spinks, who unfortunately is unphotogenic and not very quick with the quip, and suffers, too, from the most-circulated photograph of him. It is a wide, Spinks victory smile after he beat Ali. He should left his mouthpiece in. To call Spinks gap-toothed is a kind understatment. A fellow can't help if he's missing a few front teeth, but if he is supposed to be the best fighter in the world, it is bad for his image.

It may even be said that Spinks, undefeated champion, is even running third among the heavyweights in the name-recognition stakes. Moving up fast, if not in second place to Ali already, is Larry Holmes, the World Boxing Association champion by dint of licking both Earbie Shavers and Ken Norton.

The WBA endorsement may be a laugh in some important boxing circles, but it is recognized by 93 countries. The WBA handed over the title to Ken Norton when Spinks refused to fight him after beating Ali. WHen Holmes took the fight to Norton and licked him, it was with more authority than Ali ever showed against Norton in three fights.

Since beating Ali, Spinks has dumped a couple of managers and beaten a marijuana rap, but otherwise has been little seen despite the approach of his return bout with Ali in September in the New Orleans Superdome.

Spinks' public relations have been abysmal. He blew a charity appearance in New jersey without explanation, leaving Larry Holmes to receive the press. And he was a no-show in Washington last week when the City Council voted a "Leon Spinks Days" in testimony of his rise from the St. Louis ghetto. Left holding the keys to the city was a perplexed mayor.

The Leon Spinks story had all the makings of an enduring gee-whiz tale of the street kid who went to the Olympics, brought back a gold for America, moved fast through his first seven pro fights, and with only 31 rounds of pro experience licked the great Ali for the title. He still has the title, but somehow, he hasn't been an adornment to it.

Against Ali he was eager, fearless, and disrepectful of the champion so many fighters had held in awe. He could well be champion still, after their return fight in September.

Spinks is a swarmer, and he never let up against an Ali who had been getting past other fighters by practicing the little deceits he had learned in his 21 years in the prize ring. They were both played out in the 15th round, and both appeared to be only one solid punch away from getting knocked out. But it was the 24-year old Spinks, younger by 12 years, and lighter by 27 pounds, who prevailed over the old champion, now reduced to a plodder by time, that remorseful thief of youth and bounce.

That night, Spinks was a new and biggest name in boxing. But without throwing anything more than verbal punches - "I'll whup his tail if he's out of jail in three days" - Ali has established himself as the dominant figure again coming up to their return match. But except in the prize ring, Spinks vs. Ali is no contest. In Las Vegas, as a challenger, Spinks could command only a $300,000 purse against Ali's $3 million. As the challenger in New Orleans, Ali will be paid the same as the champion, $5 million. Extra care is required to remember that it is Spinks who is champ.