Golf vs. Fly Casting
When I teach a casting lesson, I always ask if the client is a golfer. I am amazed at the teaching parallels between a good golf stroke and a smooth casting stroke.
Very few sports incorporate a back stroke (as opposed to a wind-up) in addition to a forward stroke. The back swing in golf is critical: it defines the speed, pace, and tempo (and the correct starting position) of the forward stroke.
In fly casting, the back cast is even more critical. The size and speed of the rear loop determines the quality of the forward loop. Throw a bad loop behind you, and it is almost impossible to throw a quality forward loop. Top flight casters spend a lot of time looking at their backcasts for this reason.
It is the same for two-handed rods: throw a tight, arrow-pointed D-loop (as Simon G. would say, "an angry belly"), and tap the rod forward.
At the tournament level, I believe that a world-class casting stroke is every bit as technical and complex as the golf swing. I agree: Tiger is probably one heck of a caster.