A useful fly rod has a progressive action. This is an essential requirement since fly fishers require short casts and long casts. The longer the cast the greater the required bend in the rod. We can choose where to bend the rod: tip for short casts, middle for long casts, and butt for extreme distances.

It follows from this that for narrow loops all we need do is to match the bend in the rod to the size of the casting arc. It is simply not true that narrow loops are caused by small strokes and open loops by large strokes; anyone who tells you this fails to understand the mechanics of casting (or casts with a broom handle), either way you should beware of 'instructors' who teach this.

One way of learning to match the rod-bend to casting-arc, is to go for feeling: start off by false-casting a short length of line (about seven or eight yards) with a very small casting arc. Try making the loops as narrow as possible - without hauling. If you hit the rod with the line you are in the right ball park - lifting the elbow on the back (or up) cast and subsequently dropping it on the forward is one way of sorting this problem. There are others - such as casting slightly round the side so that the line fails to travel over the tip of the rod - there are advantages and disadvantages in this which will be discussed later.

Each rod has it's own maximum bend. It follows from this that it also has it's own maximum casting arc. Rods which only ever bend at the tip can only ever be cast in a small arc (assuming a narrow loop is required). With a tip action rod, once it is fully bent, the only way to cast the line further is to increase the rod tip's acceleration by extending the distance it travels. With a progressive rod you can choose to bend the rod deeper by aerialising more line. In my opinion tip action rods are inferior for this reason. Don't mistake tip action for speed. The maximum bend a rod has under load is independent as to how quickly the rod tip travels as it unloads.

To see the action of a rod, push the tip against the ground and look at the curve created. In order to see how fast it is cast with 10 yrds of line. The rod should feel 'crisp'. The crisper, the faster. You can mess around with the weight of the flyline to get different results. Check out Sexyrod Article for more information on flyrod assessing.