The weighting in new cavity-back irons has cut down on flyers from the rough. It’s the thick lies you still have to worry about.
Catching a flyer out of the rough was something you really had to be concerned about five years ago, especially with muscle-back irons. Now, with the way irons are weighted, flyers don't happen very often. The weight behind the face makes the ball come off more consistently.
For the most part, when you play a full shot from the primary rough at your course, you're gauging how close to a standard shot you can hit based on your lie in the grass.
If the ball is sitting on top, with more than two-thirds of it exposed, you can play from your same setup position and expect pretty much the same distance. The club will slow down a bit as it goes through the grass, but the reduced backspin on the shot will make the ball roll more.
Things change when the ball is down in the grass. For example, I hit my 7-iron 184 yards from a standard lie in the fairway. From the rough, I'd use a 6-iron, play the ball back an inch or two and swing down on a steeper angle to catch the ball first. It also helps to aim slightly left and open the clubface at address. You'll get more height on the shot, and the club will cut through the grass more easily.
Els writes instruction articles only for Golf Digest.