The rod has the ability to produce a torque on the fish that can change the fish’s direction and make it possible to start reeling in the line. There is a frictional force exerted on the line by the guides on the rod. 
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On most halibut rods the guides have rollers that greatly reduce this frictional force. This is almost always the case for the top guide on a halibut rod. Halibut rods are generally short and stiff to provide the greatest amount of torque possible when fighting the fish. Since the line is fished right underneath the boat there is no need to cast the line out, making a shorter rod more favorable for this reason as well. The fisherman’s wrist acts as a point of rotation to make it possible to exert a torque on the fish when the time comes to “set the hook”. The equation that explains the torque exerted on the line by the rod is τ=Fl. Where l is the distance between the line at the tip of the rod and the axis of rotation (the fisherman's wrist) multiplied by the sin of the angle between the rotation point and the tip of the rod. The force is exerted by the fish on the end of the line. At a point when the fish is about to change direction the system is momentarily in equilibrium and the sum of the torques on the system is equal to zero. Στ=0! This means that the torque being placed on the fish by the tension in the line is exactly equal to the torque that the fish is exerting back on the line.
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