The A1/A2/A3 address system for wedge distances
Instead of a clock-face swing (which Grieve says few golfers repeat consistently), he changes distance by changing setup. Address one - one clubhead between the feet, hands down the grip, weight forward - shortens how far your arm can travel, giving a set backswing length for free. Address two (two clubheads, middle of the grip) reaches roughly nine o'clock and address three (three clubheads, up the grip) gets near the top, so you focus only on chest speed for distance, not on stopping the swing.
Channel: Dan Grieve
Watch official source at 27:46Why this context matters
Grieve's alternative to the clock-face system, which he finds hard to repeat.