" 'What's he know?' " Norris said, putting himself inside the heads of a dozen or so young boys on the field in front of him. " 'He's this crippled old (man). Why should I listen to him?' "

So he relies on the cards, slightly faded pictures of himself as an Oakland Athletic, to get their attention. If they're willing to listen, he can explain that he is in a club called the Black Aces, the 13 African American pitchers who have won 20 or more games in a major-league season. Then he can point to the mound at the Western Addition's Margaret Hayward Playground and tell them that's the exact spot he began his career: "Right there, that's where it started for me."

On this particular Friday, kids between ages 7 and 12 are on the field. Norris calls them "the babies." Last summer, he took charge of a San Francisco chapter of Major League Baseball's Reviving Baseball in Inner Cities program, or RBI. The RBI program just celebrated its 20th anniversary, and one of the original goals - bringing African American kids to the diamond and eventually into the majors - finally appears to be bearing modest fruit.

After years of dropping precipitously, the percentage of African American players in MLB climbed last season to 10.2 percent after hitting a low of 8.2 percent in 2007. In 1975, the year Norris made his debut, the number was 27 percent.

This summer, MLB added a Junior RBI program in 16 cities for kids ages 6 to 12. Formally, San Francisco does not yet have such a program; Norris' chapter oversees only teenagers in RBI. Informally, he keeps a close eye on "the babies" and provides RBI coaches to help the Recreation and Park staff, which oversees this three-day-a-week introductory academy.

"We've got to get 'em when they're young, before football and basketball get ahold of them," said Norris, who grew up in the Western Addition and graduated from Balboa High School.

This is the second summer of baseball for the youngsters at Margaret Hayward, and some of the boys have an obvious feel for the game. The shortstop scoops up balls as if he has been doing it for 20 years.

"You can't tell me those hands aren't soft enough to match anyone's in the Dominican," Norris said, then asked: "You know about that stereotype?"

Because so many infielders from the Dominican Republic have to play with makeshift gloves on rocky fields and streets, Norris says, they are believed to have uncanny instincts about grounders. He says he respects the island's baseball culture but finds assumptions about baseball talent a bit restrictive. For years now, the message received by many African American kids has been: "Baseball isn't your sport."

"That's why it's so important that Mike comes out here," said Fidel Joshua, a city playground director. "They can see that he came from the same place and that he made it."

Generating interest

Nobody knows how the decline in interest started. Norris simply wants it to change. He has enlisted fellow pitcher Vida Blue to show up every now and then, as another 20-game winner. Norris says he has reached out to former Mayor Willie Brown and plans to name the RBI program in his honor. At a time of declining city funds, a political ally seems especially valuable.

But why, ultimately, is it so important that young African American kids be directed toward baseball rather than tilting toward football or basketball? The influx of Latin and Asian players seems to constitute enough diversity in MLB to honor Jackie Robinson's legacy.

Norris explains: "Baseball gives you the best chance for a long career. Basketball has how many jobs on each team? In football, you've got big rosters, but ..." He lets out a big breath and shakes his head, thinking of the injuries that abbreviate careers.

His body looks as if it went through the NFL. He needed spinal-cord surgery in 2000 to repair damage attributed in part to arthritis. But unlike a lot of football players his age, he has a decent pension.

Besides, the benefits of playing baseball don't accrue exclusively to the guys who reach the big leagues. When Norris thinks about his childhood, he remembers the sport setting a happy rhythm for the whole summer. "You can play it all day long," he said, a nostalgic smile on his face.

Keeping kids busy

For kids everywhere, but especially those in vulnerable neighborhoods, staying busy wards off bad influences. Norris tries to explain that in words, but his smile speaks even more eloquently. He loved playing this game, and it rewarded him handsomely. He can't imagine children from the same background turning away from the sport, rejecting it as part of another culture. His agenda might seem political to some, but it is fueled by very personal sentiment.

Norris can't teach the younger kids much, because they aren't ready to pitch off the mound yet. But as Norris sat on the bench during practice, he kept up a running conversation with the boys, patiently explaining to one why he had to wait for another turn at bat and successfully encouraging a pouting, gloveless youngster to play the outfield with a catcher's mitt.

Before the practice, he tried to recruit three girls at the playground, telling them they looked like ballplayers (RBI includes girls' teams.) In the city with the lowest percentage of children in America, casting a wide net is mandatory. For Norris, the instinct comes pretty naturally.

His eyes lit up when he spotted a big 12-year-old arriving for practice, someone he hadn't seen before.

"Look," Norris said quietly and excitedly, "a Latin kid. ... Good, good."

E-mail Gwen Knapp at gknapp@sfchronicle.com.

This article appeared on page D - 1 of the San Francisco Chronicle