The following is a guest article written by Rob Vollman of Hockey Abstract and Hockey Prospectus fame. Enjoy!

Other than the goalie, a team’s top defensemen are arguably the most important players on the teams. Great ones like Nicklas Lidstrom, Scott Niedermayer and Chris Pronger can completely alter the outcome of an entire season almost single-handedly. Who were the top pairing defensemen this year, how will they used, and how effective were their teams when they were on the ice?

There’s no simple answer to the first question, so seven different methods were combined. Any player who ranks in his team’s top two in the majority of the following seven categories was included in this study:
• Cap hit
• Average ice time (total)
• Average ice time (even strength)
• Hockey News Depth Chart
• CBS Sports Depth Chart
• NBC Sports Depth Chart
• CBC Sports Depth Chart

So to miss a top pairing defenseman would require mistakes on the part of at least of the front office, the coach and four major independent hockey sites. It is possible that a few borderline cases might have snuck in, though.

The resulting 69 defensemen (60 plus the extra sneak-ins) were put on this player usage chart. Explained in more detail in many places, these charts are a handy way of seeing how players are being used.

Briefly, those that start a lot of their shifts in the offensive zone are on the right, defensive-minded players are on the left. Those who face the top lines are at the top, and the more sheltered players are at the bottom. That places the key shutdown players in the top left part of the chart, and the scoring-focused players on the far right.

As for the circles around each player’s name, that’s an indication of how well the team did possession-wise with that player on the ice relative to everyone else (using Corsi). A big shaded circle indicates the team’s fortunes improved dramatically when that player was on the ice, whereas a big white circle means things took a turn for the worse. Obviously each of these outcomes are more likely at certain points of the chart than in others.

What can all of this tell us about how teams were using their top pairing defensemen? While the matter is subject to some interpretation, they fall into these rough categories in the following approximate numbers:

1. Essentially balanced usage (11/30)

The big set of teams in the middle arcing towards the left is how most teams use their two top defensemen. This arguably includes Buffalo, Carolina, Dallas, Edmonton, Florida, Minnesota, Montreal, NY Islanders, San Jose, Vancouver and Winnipeg.

They generally play together (7 or 8 out of 11), take only a slightly larger share of shutdown duties against top lines, and play in both zones. It appears to be an effective deployment more often than not.

2. Split up between one shutdown and one scoring-focused defenseman (6/30)

The second most common deployment is to split up the top two defensemen with one anchoring the top shutdown line and one being used in a more scoring-focused role. This includes teams like Anaheim, Columbus, New Jersey, Phoenix, Toronto and Washington.

I’m not convinced of this being an effective deployment, especially when the shutdown defenseman isn’t an ideal choice for the role, like Dion Phaneuf or Jack Johnson.

Even in the other cases you have to wonder if the team would have done a lot better either by assigning the shutdown defenseman a stronger partner, or by spreading out the tough minutes a little more. Anaheim and New Jersey were perhaps the only cases where the scoring-focused defenseman needed nearly as much shelter as he was provided.

For those who think more highly of this deployment, you should note that only two of the six made the playoffs, and only one in impressive fashion.

3. Both together as the top shutdown pairing (5/30)

Almost as frequently teams use both of their top defensemen together and on the top pairing like in Calgary, Colorado, Nashville, NY Rangers and St. Louis. It worked brilliantly in Calgary this year, and appears to have been an effective deployment for all of the remaining four except the Rangers. But they did made it to the Stanley Cup with this approach, so what do I know?

The beauty of this approach is the room it makes for the team’s defensemen further down the depth chart, which was a virtual necessity in at least the first three cases. I’m surprised this approach isn’t embraced more extensively.

4. Both together as a scoring-focused pairing (3/30)

Despite this being the deployment that has won the Norris trophy the past three years, only three teams deploy their top two defensemen together and in a scoring-focused role, Chicago, Los Angeles and Ottawa.

This obviously requires someone else to take on the shutdown minutes, much as Niklas Hjalmarsson and Johnny Oduya do in Chicago, or for the duties of facing the top lines to be spread out largely evenly, as in the other two cases. The risk here is that in all three cases the weaknesses of those other pairings did tend to get exposed by top opposing lines.

5. Hard to classify (5/30)

There are five teams whose precise deployment of their top two defensemen are harder to classify. This is either because their number two defenseman is hard to identify, like Boston and Detroit (who use their top defenseman in a shut down role), due to injuries and the extensive use of rookies, like Pittsburgh and Tampa Bay, or because it’s just that hard to make sense of their player usage, like Philadelphia.

Of course, none of my interpretations were meant to be definitive. Reasonable people could easily categorize each team’s usage quite differently, and it’s easy to object to the either the criteria for selecting the top defensemen, or in the results. Hopefully neither viewpoint entirely negates the conclusions reached here.

Ultimately the way a team deploys its top defensemen depends greatly on not only their own talents, but on the remaining defensemen at their disposal. While the most common approach is to use the top two defensemen in a largely balanced fashion, some teams put them together onto a top shutdown line, and as many split them up between a top shutdown pairing and a more scoring-focused partnership. In my view the former appears to work far better than the latter. Finally, a few select teams are fortunate enough to have elite talent capable of sufficiently dominating opponents in a scoring-focused role as to warrant the risk of placing more difficult duties on the rest of their blue line.