The Six Stages of the Slapshot

Preperation: The player positions the puck in front of the skate closest to the target: on average, this location optimizes the amount of energy that will be transferred to the puck on the stick's impact. It might be advantageously altered, though, according to the niceties of a player's technique or his intentions on a given shot. Shifting the puck forward, for instance, might decrease energy transfer but will make the shot go higher. (Height is also a function of the angle of the blade relative to the ice as it strikes the puck; a player varies this by rotating the shaft.) Body stance also helps set a shot's direction and height. The leading shoulder is pointed in the intended direction of the shot. For a right-handed shot, turning the stance so that the lead shoulder points more to the left of the net will make the puck go higher and to the left; shoulder to the right aims the shot lower and to the right.

The Windup: The player draws his stick back by raising his posterior arm (the one furthest from the target) and rotates both his trunk and hips to raise the blade of his stick as far behind and above him as possible. The more the trunk, hip and shoulder muscles are stretched, the greater the force generated when they are contracted. The further the stick is drawn back, the greater the velocity of the shot -- giving players with longer arms and sticks an advantage. Nonetheless, a maximum windup may not be the best idea in many game situations. "The success of a shot is not only reaching peak velocity," says Hoshizaki. "There's a trade-off: the more time you spend winding up, the more time the goalie has to prepare. People like Brett Hull score a lot of goals because they have such a quick release."

The Downswing: The shooter rotates his hips, trunk and shoulders, causing the stick to accelerate forward and downward until the blade comes in contact with the ice approximately four inches (10 centimetres) behind the puck. Hoshizaki is still studying why four inches is the optimal distance, but believes that any less reduces the amount the stick can be loaded and any more risks breaking the shaft.

Loading the Stick: At this point, the shooter continues to apply pressure on the stick by pushing the lower hand against the shaft and holding the upper end of the stick close to the body. This causes the shaft to bow and thereby store energy. (A top player can make the shaft bow four to five centimetres.) The height of the lower hand on the shaft is critical. If it is too high, the shooter will not be able to bend the shaft enough to maximize energy load: if it is too low, not as much energy will be transferred to the puck. The best compromise position is set by a variety of other factors. "The right height depends on the strength, height and skill of the player," says Hoshizaki. This is the most important stage of the slapshot because so much of the velocity is generated here.

Impact: As the movement continues, the blade catches the puck, releases energy and accelerates the puck as it clears the ice. Ideally, the puck is struck by the heel of the blade, which is the "sweet spot" of a hockey stick: because it is closer to and in line with the shaft it offers more effective energy transfer. The further out on the blade, the more torque, or twisting force, there is. That's why players can take flick shots off the tip of the blade that rise quickly but lack the speed of shots taken at the heel. During this stage of the slapshot, the shooter rotates the shaft forward so that the blade turns over until it faces down toward the ice. This motion increases the acceleration of the puck by maintaining the force on it instead of letting it roll off an open-face blade.

The Follow-through: The player continues to allow the body to rotate and move forward so the stick moves forward and upward in front of the body. Not all the energy built up in the earlier phases can be transferred to the puck, so the player has to continue to move forward and absorb the rest to maintain his balance. If he didn't follow through fully, he would fall over or risk doing damage to his muscles. As in a golf swing or tennis shot, the follow-through helps shape the action phase (that is, the downswing, loading and impact stages) and is also a valuable teaching cue. If the follow-through is good, it usually means the action phase was completed properly.

From "How Hockey Works." Published in Equinox: January/February, 1994.

All About Pucks

Nine questions and answers about that elusive object hockey players spend so much time chasing.

Q: Who invented the hockey puck?
A: Originally, hockey players weren’t picky about what they used as a puck: a piece of coal, an apple, a knot of wood, even a hunk of manure. Eventually, a rubber ball similar to a lacrosse ball was used. But -- the story goes -- in the 1860s, when games started to be played in Montreal’s indoor Victoria Rink, the ball broke so many windows that the fed-up arena manager grabbed it, sliced off the top and bottom and threw what was left back on the ice. The players quickly discovered that the new shape reduced bouncing and made passing easier.

Q: Where are pucks made?
A: Most of the hockey pucks used in Canada are made in an old building in the west end of Toronto. The offices of Viceroy Reliable Group look like they must have in the 1950s. Not much has changed in the plant either, since the way Viceroy has made pucks over the years has undergone few refinements. The machines are the same, although in some cases the controls have been automated. “The nice thing about rubber technology is it hasn’t changed much,” says Todd Bruhm, general manager of Reliable. “The hockey puck has stayed relatively the same for 50 or 60 years. ”

Q: What’s in a puck?
A: As simple as a puck looks, it’s made of at least a dozen ingredients. Natural rubber, synthetic rubber and a filler (usually carbon black, or coal dust, which also gives the pucks their black colour) make up about 90% of a puck. Additives such as sulfur and an anti-oxidant make up the rest; they help in the curing process that gives the final product its strength and hardness.

Q: How is a puck made?
A: The ingredients are poured into an automated mixer called a Banbury and then pushed though a form in a process called extrusion. This result is soft logs of rubber compound roughly three feet long. These logs are sliced into slugs, called pre-forms, which are roughly the same size as a puck but a little thicker. At this stage, the pre-forms have none of the characteristics of the final product; in fact, a key can easily be dug into them. So the slugs are placed into molds and cured at 150 degrees C for about 22 minutes.The pucks come out of the mold with knurled, or dimpled edges. The knurling gives the puck texture for better control on the stick. After the pucks are cured, the flash (the excess rubber left over from the mold) is trimmed. If necessary, logos are then applied, usually done by silk-screening.

Q: Are pucks made in Canada tested?
A: Viceroy, which started producing hockey pucks in the 1940s, can test its pucks for hardness and tensile strength, but usually only needs to when it switches suppliers. As long as the formula stays the same and there is no change in suppliers, the variation in pucks is negligible. The key to making a good puck is achieving the right hardness. If a puck is too hard, it will bounce too much and, in some cases, break the glass around the boards. If it’s too soft, it won’t respond properly and will deaden when it hits the boards.

Q: Why are some pucks made in China and Eastern Europe considered dangerous?
A: “Making pucks is not really a difficult process,” says Todd Bruhm, general manager of Viceroy. “There’s no challenge at all for us. The challenge is to set up quality control across the industry.” Some shipments of pucks made in eastern Europe have been too hard and have broken the glass in rinks. Some pucks from China have broken apart producing potentially dangerous projectiles. Bruhm believes that puck makers in these countries have trouble getting raw materials and that’s played havoc with their formulas as they’ve used inappropriate fillers such as clay. “The problem,” says Bruhm, “is all pucks look the same.”

Q: Does the NHL use the same pucks the rest of us do?
A: The NHL rule book states that pucks must be one inch thick and three inches in diameter and weigh between five and one-half and six ounces. That’s the same puck normally used by all hockey players, except younger kids, who often use smaller, lighter pucks.Although Viceroy sells almost 2.5 million pucks in Canada each year -- more than any other puck maker -- it no longer makes the pucks used in the NHL. Those are made by Inglasco Corp., of Sherbrooke, Que., using a more expensive injection process that sees the rubber compound is liquefied, injected into a mold and allowed to set. According to Andre Blanchette, general manager of Inglasco, this method allows the puck maker better control over the final product.

Q: Why are NHL game pucks are frozen?
A: Timekeepers in NHL rinks keep a bucket of frozen pucks in the penalty box with them. When a puck is frozen, a thin layer of ice forms on it, reducing the friction between the puck and the ice surface. After freezing, pucks slide better, go faster and bounce less, making it easier to puckhandle, pass and shoot.

Q: How did the puck get its name?
A: In Shakespeare’s A Mid-Summer’s Night Dream, a mischievous sprite called Puck appears and disappears without warning and early hockey players thought their projectile had similar qualities.