So does anyone know enough about flier lies to explain to me why they go farther than shots from the fairway? Just curious about the physics of it.

Less spin = more distance

I was going to say that, but Bill got here first. Next question. How do you tell if you have a flier lie? I notice on TV, that sometimes they don't know if it's a flier lie or not, and then it's a crap shoot as to what club to play.

It's a flier if, even on a clean hit, grass will get between the clubface and the ball.

Bill how is that different than any other shot from the rough?

Depends on which direction the grass is laying.........

And how deep the grass is. Balls get buried here at this time of year.

Maybe it was my imagination, but I thought I got a pretty good swipe at a few of these the other day, and they didn't get much of any movement at all. Does this kind of lie sometimes grab your ball and not want to let go?

I don't know about grapping the ball, but tall grass will sure grap the clubhead and slow it down enough to cause you the hit the ball a lot shorter distance then from the short grass.

Bill, I think you missed the point of my question. I know grass between the ball and club is what causes the ball to fly. But how do I know if the ball will fly, or if the grass is tall enough to slow down the club, and have the ball come up short? It seems that it can be either way at times, at least going by what happens on the TV coverage of the tour events. I'm thinking that if there's a "little" grass behind the ball, and not much in front of the ball, it might be a flier lie. Tall grass on all sides, it's not. Does this sound about right?

I think a "flyer" lie is what I commonly call a "fluffy" lie. It's like it's holding the ball up on the ends of the blades of grass...so there is no resistance, you are brushing the ends of the blades of grass as you hit the ball. As opposed to when the ball is sitting down in tall grass so that the blades of grass are coming over the top of the ball. So theoretically, if the grass comes all the way up over the club face, it will likely slow it down. I think.

I haven't had that experience for quite some time now.

There are several factors involved from out of the rough.

1. With little resistance and grass between the clubface and the ball, it will be a "flyer"
2. With resistance distance could be lost because of loss of velocity.

The answer should come during the practice swing(s).

I love that! If we're not "feeling it" during the practice swing, we don't have much business hitting... Take a few swings and get a feel for it. Once you're feeling it, REPEAT your practice swing. Don't add anything nor take anything away. And I really hate it when I CAN blame a poor shot on not "replicating" my nice rehearsal swing! If I do execute it properly, and it's still a poor shot... I can hopefully narrow it down to mis-judging the distance. but I still made the "intended" shot. There's some satisfaction in that!

What's a "practice swing"?
Are we supposed to take those?
Now you tell me !!!!!!

I can't speak for y'all, but in my case, it wouldn't make any difference if I did, or didn't.
For me, it would be like me throwing frisbees into the wind. Each one would have a different result, so practice swings don't do anything but make me tired.