The boy nodded.
"We should play sometime," Guthrie said. "It'd be fun. I play a little."
Both the boy and Guthrie were keeping secrets.
The boy, then 10-year-old William Graif, was actually playing for Canada's world youth chess team and was on his way to a national tournament in Windsor, Ontario. He is an internationally ranked player -- a Canadian citizen living in New York -- and one of a small number of players to become a U.S. National Master by the age of 14.
• Dress for the ALCS with Royals gear
Guthrie had a secret, too. He didn't tell William he was a pitcher for the Orioles.
"So we met that night and started playing," Guthrie said.
Guthrie and William actually started playing in the lobby after the Orioles-Tigers game. One can imagine the razzing that Guthrie took from teammates strolling by -- the image of Guthrie trying to beat a 10-year-old at chess.
"If only they'd known how tough he was," Guthrie said.
Guthrie began playing chess in fourth grade and played for his grade school chess team. But his high school didn't have a chess team.
Still, Guthrie has continued to play chess throughout his baseball career. He even introduced it in the Royals' clubhouse this season and several players, from Omar Infante to Alex Rios, can be seen playing before games.
But Guthrie had his hands full with young William back in 2010.
"Oh yeah, he beat me," Guthrie said. "He has beaten me every time ever since."
The two have gotten together several times over the past five years to play.
"I think one time I might have gotten a draw against him," Guthrie said. "Maybe not. But I do remember one time he complimented me and said it was a good game, so it must have been close."
William, of course, is thrilled to have a playing partner as famous as Guthrie.
"He's just the nicest guy, and he has a great sense of humor, too," William said.
This season, Guthrie and William arranged a match at a very special location -- atop the Green Monster at Fenway Park.
"I can't imagine that's been done before," Guthrie said.
During that match, a man named Ian who was a concession worker noticed the two playing and began observing. After the match and as Guthrie was heading down to the field for pregame warmups, he heard Ian declare that he could easily beat William.
"A hundred dollars if you beat him," Guthrie said he told Ian, "but you owe him a hot dog and a Sprite if he beats you."
With that Guthrie hurried to the field. A short time later, Guthrie was shagging balls in the outfield and he looked to the top of the Green Monster.
Guthrie, curious how the match with Ian went, threw up an inquisitive thumbs-up gesture toward William.
William smiled and returned the thumbs-up gesture: He'd won a hot dog and a Sprite.