Gene Glynn's collection of souvenirs from his life in sports is already an eclectic one. He's got a Mr. Basketball trophy, for instance, Minnesota's first, awarded for his 1975 season as Waseca High school's point guard. He's got a championship ring, earned when he managed Spokane to a Northwest League title in 1990. He's got jerseys from his days coaching in the big leagues, from teams in all four time zones: the Expos, Cubs, Rockies and Giants.

But Glynn, in his second season running the Twins' Class AAA Rochester team, last winter added something most managers don't have.

"I never thought I'd own a patent, but I've got one now," Glynn said. "How about that? I'm an inventor."

He is, though he's quick to downplay his similarity to Thomas Edison. He wasn't setting out to change the world or create a gizmo when Stance Check was born; he just wanted to help his kids hit better.

"As a father who was gone a lot, I would come home and watch my kids play baseball, and they were using different stances quite often," Glynn said of his now grown sons: Geno, 27, and Chris, 24. "And I would ask them, 'How well can you see the ball?' Hitting is very hard, and so many guys aren't even looking at the ball with both eyes."

He saw that in the pros, too — players who wouldn't completely turn their head toward the pitcher, almost relying on peripheral vision to guild their swing. When he coached under 1979 American League MVP Don Baylor with the Cubs and Rockies, they discussed the problem — and brainstormed how to correct it.

"We felt that coaches don't emphasize the eyes enough. You talk balance, footwork, cocking the body, and all that's fine. But we noticed a lot of guys had their head turned, almost to the point where their back eye was not always seeing the ball," Glynn said. "We thought parents and coaches, who were helping young kids hit, needed a tool to help remind [hitters] to get that back eye in position."

After tinkering around with glasses and masks for a few weeks, the pair came up with a plastic frame that includes small blinders above the nose, a simple device that forces a hitter to rotate his head in order to see the ball with both eyes. "If you turn correctly, your head moves slightly forward and levels out, and the nose piece disappears," Glynn said. "It sounds like an obvious concept — if you use both eyes, you'll see better — and we've had some great results with guys who have tried it."

Glynn is careful not to be a product pitchman during the season, and doesn't even push his players to try it unless they ask. But his son Geno has created a website, stancecheck.com, and promotes the device to amateur teams, from youth leagues to colleges.

"I never meant for it to become a business, but I guess it has. Geno's done a great job," Glynn said. "I don't know if I'll invent anything else. I'd like to think up something to help us win more games."