Some at the event, dedicated this peace tournament to Christian Taylor, a victim of gun violence. His funeral was this morning.
On the streets of Chicago, they're rivals.
"We all just came out to have for and have a nice day," said Joe Addison.
But for a moment on the basketball court, they're allies for peace.
"We had a chance to come together and have a good game and have fun," said Estevan Montenegro.
It happened at the Peace Basketball Tournament.
"It's really all about pulling these young guys out of their comfort zone having them to network and communicate with one another," said CeaseFire's Tio Hardiman.
In another attempt at stopping gang and gun violence.
"We look at sports as a place where people can come together, get to know each other," said Thomas. "Once you know someone we believe it's hard to kill someone you know and love."
Thomas grew up on the Chicago's West Side not far from Christ the King Jesuit College Prep which hosted the event.
"About 80 percent of our kids have be affected by violence," said organizer Christopher Devron. "Some way or another, they know someone who's been a victim or a violent crime."
It's the second peace tournament in as many months.
"Basketball's just the hook," said Father Michael Pfleger of St. Sabina Church. "We've got to get jobs, we've got to get education and we've got to care for these guys beyond basketball most important thing."
The first was in September at St. Sabina church.
"We made history, so we want to get it throughout Chicago," said Patrick Vance.
That's the hope of former west side gang member 52 year old Clifton Booney McFowler, who spent 27 years in prison after being convicted of murder.
"I want to be able to save at least one if I can't save millions of kids in this community from taking the route that I took," McFowler said.
In an effort to help old enemies become new friends on the way to non-violence.