The rules do not require baserunners to slide, but the competitive Yarbrough did it anyway - three times.
"I had to be safe," he explained.
Many play the sport rather laxly. It is more a social gathering than an athletic contest, often just a beer league that is an homage to the days of recess and gym class, players say.
But most teams have their own version of a guy like Yarbrough. Or, as he is quick to point out: "That's Coach Yarbrough."
Yarbrough took a game last week extra seriously: His undefeated team was in its league semifinals.
Yarbrough was dressed in his team's powder-blue T-shirt, which features the silhouette of a provocatively posed woman booting a kickball. His raiment also included a pair of white sneakers (stained brown from the field's diamond dust), sweat-soaked gym shorts, and a pair of Underarmor gloves, for grip.
Considering that a player once competed in a hot dog costume, the gloves did not turn many heads. It is the games themselves that are the draw.
"We were shocked with the success of kickball," said Jason Cooper, codirector of Philadelphia Sports Network, a recreational sports group. "It's one of our most popular sports now."
Recreational leagues have kickball seasons year-round, charging about $50 per player per season. Depending on the league, teams register about 20 players each, with up to 36 teams playing in a given season.
Many leagues find themselves filled to capacity, with not enough fields in the city to support more games, Cooper said.
Philadelphia's fields help breed a culture of kickball. Designed for Little League games, they are often too small for adult softball.
Offices and groups of friends sometimes field teams of their own, but much of kickball's new popularity is due to individual players looking to make new friends. Nearly half the kickball players in Cooper's league are solo registrants.
