We've all heard different rules -- one drink an hour is safe, maybe a couple with dinner. But what a lot of people think is safe this holiday weekend might be pushing it.

At the GreenJackets game: good baseball, friends and beer flowing almost freely.

It's a recipe for a lot of fun -- but how many beers are ok -- to stay safe when it's time to head for home?

"If I'm driving, I don't [drink]," a fan said.

A lot of people say they have designated drivers -- but others say they drink in moderation.

"Pretty much two or three, that's about it," another fan said.

Just a few beers, but Dr. Mark Newton says they might be enough to pitch you into the slammer -- or worse.

"The only safe amount when you're driving is none," Newton said.

And what if you left the keys at home? Newton says you should still beware. Too many drinks can knock you out of the game.

But he says you don't have to stop short of drinking entirely, if you stay reasonable.

"There is a safe amount you can metabolize of one drink an hour," he said.

It's advice some fans can drink to.

"Just one," a fan said. "to have with my hotdog, then I enjoy the game. That's it."