You have to ask what you're trying to 'pull' in tems of force exerted. All these different rods with different TCs will exert a different force for various reasons. There's a good article on BFW about this. My 11 ft custom Harrions are 1.5tc but will exert a certain amount of power while 'cushioning' lunges. I'd prefer that to a nominally 'stronger' 2lb tc rod.
Good point. The amount of power you can exert with a rod is not determined solely by test curve. A rod which reaches a quarter circle under a loading of about two pounds will, in theory, apply more pressure than a rod of equal length which takes just one and a half pounds to pull to the same curve. So far so good. Now for the odd bit.
Most rods are held about twenty inches from the extreme butt. The rod acts as a lever, with the fulcrum at the butt. It follows therefore that the more powerful the rod, the greater the leverage on the angler's arm. Matters are further complicated by rod length and shape of curve. The longer the rod, the more leverage is applied, all other things being equal. The tippier the action, the further from the fulcrum is the start of the curve.
An angler can apply the most stopping power to a fish with a handline. As soon as a rod is involved, the application of power is transferred to a point some distance away from the angler's hand, and the further it moves away, the greater the loss. What happens when you use your free hand to support the rod a couple of feet above the reel position? You relieve the strain on the rod-holding hand, that's what.
A through-action rod bends further down towards the butt than a tippy one. A softer rod bends further than a powerful one. The nearer to your hand the bend comes, the more efficient the use of the force you apply becomes. That's why people find they can land fish more quickly on through-actioned rods of sensible length than they can with more powerful or longer ones.
The only reason for increasing the stiffness or length of a rod is to enable casting heavy baits or leads, or to reach further.
