According to a press release, King said: "I love old-school baseball, and I also love the way people who've spent a lifetime in the game talk about the game. I tried to combine those things in a story of suspense. People have asked me for years when I was going to write a baseball story. Ask no more; this is it."
Honestly, I wasn't asking, but I'm sure baseball fans everywhere will rejoice. The good news: it's a novella, so it's a lot smaller than King's last novel, the 1,000-page plus Under the Dome.