Because hockey sticks come in so many shapes, it can be hard to make sense of it all. One feature of particular importance is the blade – the only point of contact between the player and the puck. Players attach a lot of importance to the way it is curved. Looking at the Koho (yes it uses older curves as examples, but it’s still relevant) sticks in the figure bellow, you see that each one carries a unique curvature pattern. There is more to a curve than left- and right-bend indeed.
Figure 1: a few sticks by Koho™
The stick blade, a curved and twisted surface, is complex enough that it can’t be precisely described in just a few words or numbers. Nonetheless, there are some key aspects that need to be considered, the first of which is the amount of curvature in the blade. The more U-shaped it is, the more pronounced the curve. Hockey leagues such as the NHL impose a limit on the amount of curvature:
The curvature of the blade of the stick shall be restricted in such a way that the distance of a perpendicular line measured from a straight line drawn from any point at the heel to the end of the blade to the point of maximum curvature shall not exceed three-quarter of an inch (¾”). NHL Rulebook 2007.
If you can’t picture this strange verbiage, the following drawing should help:
Figure 2: measurement of curve depth
The rule says that the red line should not be longer than ¾ of an inch, or 1.9 cm. Some people use the dime technique (not quite ¾”, but close) whereby the coin shouldn’t slip vertically underneath the blade when its lying against the floor, but nowadays NHL referees have fancier measuring gadgets to control illegal sticks. Note that the ¾’’ figure is an increase from ½’’ as of 2006. We will discuss the implications of that rule change later.
A second key aspect is where the curve begins on the blade. A blade can be curved like a circle, smoothly and uniformly, but sometimes it is not. Take a look at the Reebok™ and Easton™ sticks in Figure 3: the “Yzerman” stick has a curve that begins in the middle of the blade whereas the “Amonte” one starts at the heel. These are called “center” and “heel” curves, respectively. A third one is called the “toe curve” and has a bend closer to the end of the blade. While the difference between center- and heel-curves is mostly a matter of preference (hockey players can be very picky), a toe-curve makes scooping the puck away from someone else a little easier.