1930s, which had a progressive bending curve. Sometimes the term parabolic is more specific used to note the specific type of progressive bending curve as was found in the Parabolic series. A common way today to describe a rod's bending properties is the Common Cents System, which is "a system of objective and relative measurement for quantifying rod power, action and even this elusive thing ... fishermen like to call feel." The bending curve determines the way a rod builds up and releases its power. This influences not only the casting and the fish-fighting properties, but also the sensitivity to strikes when fishing lures, the ability to set a hook (which is also related to the mass of the rod), the control over the lure or bait, the way the rod should be handled and how the power is distributed over the rod. On a full progressive rod, the power is distributed most evenly over the whole rod. Line weight The line weight of a fishing rod describes the optimal tension along the fishing line the rod is designed to handle, usually expressed in pounds or kilograms. A fishing line's "breaking weight" describes the maximum tensile force that can be exerted before the line breaks apart, while the line weight for a rod describes as the extent of bending force that the rod can support. Fly rod weights are typically expressed as a number from 1 to 12 written as "N"wt (e.g. 6wt), and each weight represents a standard weight in grains for the first of the fly line, established by the American Fishing Tackle Manufacturing Association. For example, the first of a 6wt fly line should weigh between , with the optimal weight being . In casting and spinning rods, designations such as "8-15 lb line weight" are typical. Lure weight The lure weight of a fishing rod describes the optimal weight range of terminal tackle (mainly the bait and hook/lure, and any attached float, sinker, swivel and/or heavy leader), usually expressed in ounces or grams, that the rod is designed to handle in order to achieve good casting outcome. Casting lures heavier than the designated weights might result in the rod tip breaking, while lures that are too light might have trouble with casting distance and accuracy. Number of sections Rods that are one piece from butt to tip are considered to have the most natural "feel" due