Cecil Harris, author of "Charging the Net" and two other sports books, joins Thirty Love host Carl Bialik to talk about his forthcoming book on black tennis players, "Different Strokes," why he thinks 2018 might be the Williams sisters' last year on tour, and which young black players he thinks show the most promise. Produced and edited by Jorge Estrada, with music by Lee Rosevere. Harris on Twitter: https://twitter.com/allmyyankees