Line Twist is something that can occur as a result of change of plane casts, such as Oval Casts, the Belgian Cast and Spey Casting. What happens is that the spiral rod tip movement puts a twist in the flyline. What bothered me about this explanation was that some of my friends – Morsie, Stuntman Ronan and Chris Dore – have all informed me that they don’t experience twist with Oval Casts.
So I’ve looked into this a bit deeper and, what I now believe is happening, is that while the twists always occur, it’s only when you release tension in the line hand do the twists move from above the line hand (where they later cast/shoot out the rings) to below the line hand where they twist the slack line that lays between the line hand and the reel.
Personally, I often subconsciously slip a little line as the loop straightens, this helps cushion the rod tip from, what we on the Board technically call, the “boing” 🙂 which is the small surge of energy dissipating at “loop straight position”. In order to slip line we release tension in the line hand, which in turn allows the twists that are above the line hand, to move to below the line hand where they create problems.
Consequently if you want to avoid twists, then maintain a tight grip to the line with the line hand, particularly during transitions between strokes. I think that the problem is slipping a small amount of line – as opposed to shooting longer lengths. If they do occur then the simplest method of removing them is to shoot the line fully to the reel a few times, this moves the twists away from the reel and up and out of the rod where they unravel.