We fly cast with a long flexible lever, the effect of which is to amplify the movement of our rod hand – for gain or loss in the (fly line) outcomes of our movements. We get an added bonus from desirable movement of the rod hand and we get extra penalties from undesirable movement of that hand. 

What is desirable and what isn’t depends on the type of cast and the intended outcome(s) we seek to produce. However, for the purposes of this post let’s assume we are intending to make a medium length overhead cast using a basic or foundation stroke. Let’s also assume we are using a nine foot, 5wt rod. I’ll start with the rod.

Just for the heck of it I wanted to get an indicative measure of the relative distances travelled by my rod hand and my rod tip. To do this I knelt down in my backyard and, rotating my upper body while leaning over into a position much like a standing cast, I stuck a nail in the ground about where my hand finished on a pantomimed back cast and another where the forward cast stroke ended. My tape measure said they were 430mm apart.

Using the rod hand backcast nail as my reference I next marked the back cast rod tip position and then its position at the end of the forward cast. The tip had “travelled” 2790mm or nearly 7 times the distance travelled by my hand. To be clear this exercise was intended to render indicative results and not exact measurements of an actual cast which allowed for rod bend which decreases and then increases the rod effective length during a cast. The point is that the amplification of hand movement is extremely significant. I know we know this in a general way but I’ll bet the actual multiple raises a few eyebrows. 

On to weights. The first thirty feet of a standard 5wt fly line should weigh about 9 grams. Let’s call it a 5wt double taper and estimate that when we carry sixty feet of line we are towing about 18 grams of line. Let’s broaden the picture to put that in another throwing context. If I was tasked with making an accurate throw to a target 20m away with either a table tennis ball or a golf ball I would choose the golf ball. Guessing you would make the same choice. With the golf ball I could do it using a variety of throwing movements from underhand to overhand to side arm. (FWIW I can still throw a golf ball a helluva lot further than I can cast a fly line.) With the table tennis ball I’d be limited to a carefully executed overhand throw and even then I might not make the distance without wind assistance.

A golf ball is about the same size of a table tennis ball. The golf ball should weigh around 46g and the table tennis ball should weigh about 2.7g. A golf ball has 17 times the weight of a table tennis ball. Thirty feet of my 5wt DT floating line weighs about as much as 3.3 table tennis balls and so 60 feet of that line weighs as much as 6.6 of the same balls. 

So, when we set out to make an accurate fly cast, out to say 20m, every 10cm (4”) of rod hand movement produces about 70cm (28”) of rod tip movement. To make the cast we are throwing the equivalent of about 5 or 6 table tennis balls. The margin for error is pretty small and we all know from experience that as the cast length increases the margin for error gets smaller. 

Putting this small weight and highly amplified distance into a movement context should help explain why the answer to meeting the demands of getting it right lie in doing some things pretty counterintuitive to what throwing balls and stones has taught us. The primary counterintuitive thing is to use less effort rather than more to throw further. 

We need to optimise the extent to which we tow a straight line in straight lines (mechanics) and to do that we need to move as accurately as possible. To do that we need to slow down our movements because we move more accurately when we move slower that is, when we exert less effort.  If I snatch a glass of beer off the bar and drive it toward my mouth the result will be lots of spilled beer – a clumsy mess. A friendly observer in Oz would probably say, “Shit mate. Take it easy.” Over powering a fly cast produces the same outcome and I offer the same friendly advice to all willing to listen – myself included.

Both the distance amplification of the fly rod and the light weight of a fly line permit and demand that we slow down our casting movements. That means using less effort. We can apply X amount of accelerating Force using strokes of different lengths – short stroke equals more effort and longer strokes equal less. Playing around with minimum effort/power casting drills can be fun and informative. 

Efficient movement to produce mechanically efficient fly casts is the end game. Mastery of a movement is achieved and demonstrated by the removal of all superfluous effort.