Sisterly Driven Intervention for the Spurs?

What's the big deal about the San Antonio Spurs basketball team getting a little Sisterly support during the NBA Playoffs?

We've got plenty examples of Sister Sports Fans in the book! There are memories of sisters playing basketball, not just cheering the game. And playing softball, running and bob-sledding, too!

Based on all the stories collected, though, the sport of choice among sisters must be baseball.