On a winter’s day at the end of 2005, Gregory Howe, a 34-year-old English teacher at a school in Cheltenham in southwest England, turned to the website with the International Tennis Federation’s rankings and realized that time was running out on his childhood dream.

An amateur tennis player, he had occasionally attempted to qualify for Futures tournaments, the bottom tier of professional tennis, during school holidays. But his ambition was simply to get the single point required to achieve a world ranking. Achieving this required battling through the qualifying tournament and then winning a match in the main draw, which had proved beyond Howe’s skills in more than a decade of sporadic attempts.

So he decided to quit his job and dedicate an entire year to the pursuit, which he documented in a book, “Chasing Points: A Season on the Pro Tennis Circuit,” to be published in the United States on Monday.

“I had this epiphany,” Howe said in a phone interview. “Well, I was a teacher, so probably a bit of a breakdown. But I realized I’d never given myself a really good chance to see how good I could be. And now, at 34, it was make or break.”