By power we mean the ball speed a stick can generate when hitting or slapping the ball given a constant swing speed.
Ball speed is obviously important in many aspects of the game and particularly crucial when shooting at goal or passing over longer distances. There is a direct correlation between the power a stick can generate when hitting or slapping and the shaft stiffness of the stick. The stiffer the shaft of the stick the more direct transfer of energy there is onto the ball and the faster the ball will travel. The shaft stiffness of the stick is dependent on a number of factors.
Firstly; the materials that are used to make the stick. No metallic substances are allowed in the production of hockey stick and so the materials used are composite materials ranging from fibre glass to various aramids and carbon. Carbon is generally the most effective material to stiffen a stick. It is very light and has a very high tensile strength. It does however significantly harden the feel of the stick as it is not as absorbent as other composite materials and also relatively brittle when subjected to impact. It therefore has to be combined carefully with other materials in order not to negatively impact the feel and durability of the stick.
The second main factor influencing shaft stiffness is the lay-up of the stick. By lay-up we mean where and how the different materials are placed in the shaft of the stick during production. As a stick is not a uniform shape the there are different torsional stresses in different areas of the stick on impact with the ball. The placement and fibre direction of the different composites materials is critical to get the maximum possible transfer of energy onto the ball.
Thirdly the shaft stiffness also affects the quality of the bond between the different materials. This is in turn impacted by the quality of the resins used and process used to impregnate the fibre and also the moulding process.
The power a hockey stick can generate when hitting or slapping the ball is directly dependent on the shaft stiffness of the stick. Shaft stiffness is in turn dependent on the materials used to make to make the stick as well as a number of factors in the production process. Sticks with high shaft stiffness will have more carbon as this is the most effect material to achieve stiffness. The carbon percentage of a stick is will give an indication of shaft stiffness within a range of sticks but is not useful for comparing across brands as the shaft stiffness is also dependent on a number of other factors - stick lay-up (positioning of materials in the shaft, quality of materials, and how well the materials are bonded during production)If carbon is not used effectively it can negatively impact on the feel and durability of a stick. When choosing a stick, players who prioritise power for hitting and slapping will place a big emphasis on the shaft stiffness of the stick. Improved shaft stiffness is the main feature you are paying for when you move up in the range.