We have all heard about the Straight Line Path (SLP). Physics and common sense tell us that it is most efficient to apply force to something in a straight line if we want to move it in one particular direction. 

If we optimise the amount of force applied in a straight line we optimise the efficiency of our casting. Combine that with slack minimisation and we get “use less effort to cast in straight lines with straight lines”.  Simple and fundamental to efficient casting.

Tracking

The efficiency of the straight line applies in several ways. From a practical point of view, and especially for any overhead cast, we need to consider tracking  – the extent we make the rod travel from back to front or front to back in a straight line ie. 180degrees. How good is our tracking? Three ways to find out.

The simplest form of tracking exercise is using a straight reference line on a structure and to move the rod along it in slow motion watching what happens. A string stretched between two trees at the appropriate height will do the same job. 

Alternatively we can cast beside a straight line on the ground and see how the fly line lays out in relation to it – for both back casts and forward casts. The shape of the line on the ground gives us a clue about the shape of the movement which produced it.

Here’s something a little different. Watch yourself slow motion casting in front of a mirror. I don’t need anything in my casting hand but anything from a pencil to a butt section would do.  Go through each of the casting stances you use and watch where your rod hand goes. I’m fortunate enough to able stand in an open doorway with a mirror in front of me. The door frame, mirror and my knuckles show me what is and isn’t straight about my hand path. Big lesson? Rotate your torso first and then extend your arm. In biomechanical terms it’s the proximal to distal thing, making sure to get the first out of the way of the second.

The SLP and Rotation

Again this is about optimisation. The longer we can keep the rod tip moving in as straight a line as possible the more efficiently we cast. If we make the rod tip dip below or rise above the SLP we lose efficiency. If we make it do both during a casting stroke we are asking for tailing loop trouble. 

Moving more slowly helps us to move more smoothly and accurately. My self talk script used to be “start slow, go easy and finish full”. This year I changed it slightly adding “stay easy” between “go easy” and “finish full”.

The extent of your SLP can be shown by using the same reference line on a structure as I mentioned for tracking. I use a sleeved fly rod broken into half sections. The sleeve provides protection and containment as well as having a tip that’s easy to follow. Same sort of exercise, move in slow motion and watch for deviations above and below the reference line. On the forward cast I use everything from a hard stop high to a full lower arm extension at the finish.  I can likewise check out a full or partial arm extension on the back cast. My house has a pergola with nice long beams at a handy height.

It comes as no surprise that it’s fairly easy to stay straight during translation. Rotation is where it gets harder. It’s where windscreen wiper casting strokes are made. It’s always been a problem and over time different solutions were written into the religious texts of fly casting. First it was “use no wrist” – book under the arm and 10-12 strokes. Then it morphed into using a bit of wrist but stopping high and hard. Then we started having to cope with the heresy of wristy “stopless” casting.  Setting the wrist free is a risk reward undertaking. The reward is a longer stroke length and the risk is moving out of the SLP too much and too soon. The harder you go the higher the risk – ergo go easy and stay smooth.

Just because I could I got an old rod butt, some masking tape and a tape measure. Using a sliding door frame as my horizontal line I made some slow motion (basic or foundation) forward casts movements with full lower arm extension. I marked out the distances travelled by the top of the rod butt during forearm extension and then wrist/hand extension. 

The total distance covered rounded out nicely at about 100cm. The forearm extension and the wrist/hand each contributed about 42cm. The other 16cm probably came from the upper arm rotating down and then up again. What stands out? The wrist/hand contributed as much as the forearm and a scary 42% of the movement overall.  By moving slowly I was able to optimise the straightness  and length of the SLP. I have worked long and hard to do this in my practice and fishing casting.

Why would I want to use a religiously hard stop, much less one coupled with zero wrist? Not saying this is for everyone but am saying each of us must find what amount of movement of which body bits we can use before things start getting untidy.

I have written more than enough about getting the “wrist snap” out of it.  More recently I watched a video of Simon Gawesworth making static roll casts and imploring the viewer to do it effortlessly. Static rolls are among my least favourite casts but he got my attention with the effortless bit. Connecting some dots I used the static roll with maybe 30’ odd feet of fly line and 10’ of leader out and I played around until I could get nice loops and full extension by delaying uncocking/releasing  my wrist until my forearm extension made it happen “automatically” – without any conscious effort. Ok, nice, so how much is transferable to dynamic rolls and overhead (or any other plane) casts? 

Here’s some practical things to play with in the search for what works for you. Make static rolls, dynamic rolls and standard casts while playing with varying amounts of wrist at different cast distances. The wrist can be anywhere between frozen solid to completely free as in a flailing motion. See what happens. See what you prefer. I know what I like and when and I still play around with it all – well, not much of the frozen wrist stuff.