Some people get mugged in the street. Others are attacked in dark alleys and bars. I got mine on the basketball court at the YMCA.

You know the place -- that gleaming new brick-and-glass building at 17th Street and Rhode Island Avenue NW.

His name, for this story, was Ace. Little guy with a quick jump shot and, apparently, a hair-trigger temper.He also is known around the Y as a whiner, a man who moans at every piddling foul.

We were playing our usual four-man-to-a-side full-court game on the scaled-down Y floor one Saturday afternoon. The count was 11-all, and the next team to score, under Y rules, would win the game and keep playing. Losers would have to sit down, on this day for at least another 45 minutes in a gym full of players eager for action.

That's pressure.

Ace's team had the ball. Well, actually, Ace had it in the right corner, where he took one swift step around the man guarding him and drove the baseline, straight for me.

I held my ground, but before he got close, Ace bounced the basketball off his foot and out of bounds.

Our ball.

But nooooooo, Ace the Whiner was not about to give it up that easily.

"Foul," he yelled, insisting that he had been pushed from behind.

Gimme the ball, crybaby," I yelled right back. "You've been crying the whole game."

"Oh, yeah?" he said, adding some terribly naughty nouns. Then he punctuated the profanity with two of the fastest right hands I never saw.

Pow, pow.

I don't remember much after that, except that several bodies quickly stepped in and broke up a onesided tussle. I believe they call it being "out on your feet."

I think we lost the game, because thenext thing I was coming to under a shower and wondering how I got there. The jaw was a little tender and, I must admit, I was embarrassed.

One of my teammates was changing at anearby locker and tried to comfort me insisting I was not Ace's first victim. "He does that all the time, and he's not the only one. I play in a game at lunchtime and you ought to see the lawyers go at each other. This place is a zoo."

Yes it is. So, too, is the court at the Community Center in Rockville every Tuesday and Thursday nights when pickup games are scheduled.

"I have to lock the gym door at 7:45 to keep 'em from running off our heart-attack rehabilitation class," said Herb Resnick, the JCC's director of health, physical education and recreation. "And when I unlock the door, it's like 100 animals stampeding."

Unlike the YMCA, where players of all skill levels can get into the games, the JCC has a caste system. One game features the better players -- bigboy thumpers, ballhandlers and shooters in, usually, full-court games.

Assorted stiffs beat on each other in half-court games.

Al Weisenfeld, a 47-year-old management analyst at the Department of Energy with a wicked two-handed set shot, plays half-court. The wildest games are against the Israelis, he said. s

"They get five guys on the same team all talking Hebrew," Weisenfeld said. "All you hear from every one is, Doovie, Doovie'. Everybody's name is Doovie, and when one guy shoots, all of 'em go for the rebound. It doesn't matter who's in the way or who they knock over to get there. They just go for the ball."

Mitch Reisberg, a Rockville accountant and a regular in the JCC's fullcourt games, said there are two types of games at the JCC: "one for the animals -- us -- and one for the week-hearts.

"Every once in a whole you get a jerk who wants to fight, but we've got guys with wives and kids. Who wants to go home with their face rearranged? But it does get rough.

"If a guy gets behind you you come back an go over his shoulder. Usually, it's boom, followed by I'm sorry'."

At the YMCA and the JCC, there are certain basic rules most players follow.

Reisberg said, "Never pick a guy for your team who's wearing Earth Shoes or purple Converse. If you've got height, anything over 6-foot-3, I want you on my team. Never pick a guy you don't know."

I have my own set of commandments at the Y.

Never choose a man wearing black socks. Always pick a man with sweat bands on both wrists -- he's bound to be a pure shooter. Never drive the lane unless you're prepared to pay in pain. And now, of course, never call Ace a crybaby.

Still, my punchout at the Y pales in comparison to the tale a colleague, David DuPress, related

He was playing in a pickup game as a teen-ager at a Seattle recreation center when a fight broke out between two players there was a puncher and, like me, a punchee.

The punchee left the gym. But 30 minutes later, he came back, stepped onto the court and called time.

Then he pulled a gun and shot the puncher four times.