It's not clear whether the NBC Sports "Science of NHL Hockey" segments will do more to teach kids about physics using hockey, or teach anyone about hockey using physics.

In either case it's a refreshing initiative and a great jumping off point for a fun topic: The little, often unseen biomechanic factors involved in a hockey game.

There's a kinematics preview video with Matt Moulson embedded below, you can watch several of the other segments here, and read a good New York Times backgrounder on the initiative here.

If you have never played hockey, or have never played it on ice, you might not be aware of the many little physical things that influence a player's ability to pull off an action which is done with a simple two-button combo on NHL 12. (Of course, even when we do play, it's no guarantee we understand what's going on at a vastly more skilled level.)

The point is there is so much to learn about this game. This topic is one I don't see covered enough yet have always wanted to explore more here using the collective wisdom of crowds.

So please see this post as an invitation and jumping off point on the subject if you're so inclined. After all, physical intelligence is a beautiful thing, and I'd wager it's a major unspoken reason so many of us watch sports.

I'd also suggest hockey, unlike basketball or football or baseball, is a little unique in most of the U.S. because most adults did not experience playing it as kids and don't have that basic physical memory to turn to as a reference point when comprehending an individual move. (It's almost the inverse of soccer in that way.) Hockey's a fascinating spectator sport that doesn't require any prior experience to evoke that fascination.

(I may be unfairly singling hockey out simply because I know it best and in fact am far more physically ignorant about the other sports. My baseball-playing college roommate and I used to have great discussions trading notes on the physics of baseball versus the physics of hockey.)

Matt Moulson in HD Slo-Mo







I've found this sometimes leads to interesting conversations with newer fans -- accustomed to the ease of running and stopping on foot -- who don't quite understand the speed and difference at work on ice skates. (On that note, the difference in forces between ice and roller hockey are significant. Ice is a game with as little friction as possible. Roller hockey introduces much more friction, both with the puck and skating and goaltending, but also with the areas of the body that feel that friction.)

This is not meant as some sort of lecture to those who haven't been lucky enough to play hockey, or to play it on ice. I just think this topic opens up whole new ways to think about the game and marvel at those who master it. Ideally this might even serve as an impetus for our community members to share observations and ask questions that come up now or in the future.

Why Did He Do That?!

The most commonly asked question -- and its many profanity-laden variations -- has perhaps the easiest answer: He didn't mean to.

With rare exceptions (the Blake Comeau COZO, the Brian Rolston 80-foot long dump), when a player does something puzzling it's not necessarily because he meant to do what you just saw: It's because he meant to do something else. But a lack of ability, time, space, or a miscommunication kept him from pulling it off. Whether it's Rob Schremp in the NHL or that dazzling guy you saw at rec hockey that one time, most players stop rising once they get to a level where they can no longer do what they did at the previous level, and are unable to adapt that new reality to their new surroundings.

But aside from talent, there are plenty of other possible factors on any given play. A throwaway example: You might hear upon a close rebound stuffed low into the goalies pads, "He really needs to learn how to lift that shot." Rest assured, NHL players know how to lift their shots. Even stay-at-home defensemen know how to lift a shot in tight. It's just another thing entirely when a defender is pushing on your back, you're weight involuntarily shifted to one leg (if that) or you're at the extent of your reach on the backhand, you're battling an ankle or wrist or thumb injury that makes in-tight maneuvering difficult -- and oh, by the way, you're on the 60th second of your shift.

Basically, there are countless variables in one shift that can make an NHL player appear to be unable to do what he can in fact do in better conditions. Body positioning, momentary fatigue from sprinting, aches, opponents' interference -- remember, they want to use all of their power to prevent the attempt -- and the underlying pressure from the girlfriend to buy a ring may be at work on any given play.

"Why didn't Michael Grabner go for that long pass? He's faster than that!"

It's possible he's at the end of his shift, it's possible he just took a whack on the ankle that made acceleration momentarily difficult, it's possible he was just hollered at from the bench to change. Basically, of all the possible explanations, the least likely is that Grabner suddenly sucks, suddenly decided to tick you off, or suddenly decided that he no longer cares.

"Why didn't he level that guy?!"

It's possible he was conserving energy on a long shift. It's possible his feet weren't positioned for a good wallop and he had to play it safe. It's possible his partner made him aware of a threat that would make going for the Phaneuf not worth the risk of a scoring chance allowed. It's possible he has a wonky shoulder that demands respecting the marathon in favor of the sprint.

We tend to fall into the trap of thinking bodychecking is as easy as pushing the B button. It's actually one of the toughest skills to master at the NHL level, and that's a major reason we see so many NHLers do it poorly and end up with Shanabans: Sometimes they don't think they're doing anything risky or wrong -- but that's because they did what they've always done in hockey, except now the speeds are that much greater and require that much more pinpoint accuracy.

Beyond being punishing to one's own body, bodychecking requires good skating, good anticipation and good agile reaction. That's what makes the open-ice hit the rarest of forms: The checker is chasing a puck-carrier who has any number of alternative directions to turn to, and the burden is on the checker to not turn a sudden move into a knee-on-knee or worse.

Why Can't He Catch Him?

Speaking of skating, that's often the biggest differentiator at any level of hockey. Prospect after prospect has hit the wall for lack of this basic yet essential skill. Michael Grabner is that rare player whose hands need to catch up with his skating rather than the other way around.

John Tavares' skating -- one of the few knocks during his draft year -- has improved remarkably since his rookie year, but I'd bet it's not all due to leg strength. There are people with very strong legs who can never figure out how to put it together on ice.

Skating at its heart requires a delicate balance and communication between the feet and upper legs (obviously) as well as the core muscles and upper body balance, including overall posture. It's hardly a natural activity unless a player was born in skates, and often players progress very far with an inefficient skating style that needs tweaking. There are a lot of styles and a lot of different schools of thought on how best to maximize skating -- and one's size (of limbs, of torso, etc.) and natural attributes affect which approach is best -- but the best skating coach is someone who is both excellent at identifying inefficiencies and in conveying how a skater can get in touch with those small posture and muscle movements that will make a difference.

"Why didn't he STOP that shot?"

The least understood position is probably goaltending. There are physics, mobility and anticipation factors that look deceptively simple from the outside because the goalie is essentially in a confined area. But there are multiple approaches to the position, and whether a goalie tends more toward butterfly or "blocking" style also affects how they will look to the outside observer in certain situations.

(Picture Ed Belfour or J.S. Giguere staying big and square in percentage-lowering, angle-playing position up in their crease versus Henrik Lundqvist sitting further back, making reactive save after reactive save, versus Martin Brodeur mixing an unpredictable variety of toe, pad-stack and traditional butterfly saves)

Amusingly, some of the "greatest" saves are saves made when a goaltender is actually out of position but takes great pains to bail himself out. That in itself captures the deceptive nature of the goaltending position, where sexy and highlight reel is not always good.

On that note, one thing worth remembering is that a goalie's movements are designed not merely to stop (or in case of a screen, increase the odds of stopping) that first shot, but also to best prepare him for the rebound if there is one. Rebounds are a huge source of goals in hockey, so minimizing them is ideal but not always in the goalie's control. Being in position to handle them is what separates the elite from the rest of the pack.

Sometimes the goalie's just not good. Sometimes he's unlucky. Sometimes he's screened and sometimes the puck just isn't hitting him in the chest as much. (Incidentally, because of the pushes and slides, playing goaltender on roller hockey is quite different from on ice. Ice goalies carve up their crease each period to create grip that is still nothing compared to the friction that a roller surface provides.)

That's enough out of me. Refute, debate, add more -- or just see this as an open invitation to go into this topic at a later date when the right situation arises. (Note: Injuries are also a fun topic. Knee, shoulder, wrist, thumb, groin and abdominal injuries have taught me far more than I ever wished to know about how they can affect basic movement and performance.)

To close on a more concrete note, John Tavares is amazing because there are so many things he does with the puck that most players in the world would not even think to do at any level, let alone successfully pull off. Add to it the eyes in the back of his head and ... awww, sick. I don't think we'll ever understand him. But some of these other guys, we can at least try to guess.