When evaluating a player, not just a defenseman, in general, I like to take two different approaches: Numbers, and the eye test.
Obviously ice time is the most important statistic: An elite defensemen will chomp minutes. But you wanted more, so here's a nice long rant for you. :laugh:
Here's a really easy way to get a feel for a defenseman if you don't get the chance to watch them play: Usage charts. They can be found here.
With advanced stats, you can't really compare two players on different teams in pure numbers, but rather their ranks within their team. So here's how to read this chart: The further to the left a player is, the more they start in their own zone rather than the offensive zone. The further up a player is on the chart, the more difficult competition they play against. If they have a blue bubble, that means that their Corsi (a metric that, basically, describes how well they drive possession in the right direction) is positive. If it's a big blue bubble, it means that they are really, really good at driving play, relative to their teammates. The same holds true if it's a big red bubble: it means they stink at driving play relative to their teammates. The smaller the bubble, the closer they get to zero from either direction.
Those charts are the quickest and easiest way to look at usage: zone starts, quality of competition, and Corsi. Players who play harder minutes tend to have bubbles in the top left of the chart. Easier minute are the bottom right.
If the player starts a lot in their defensive zone and have a high quality of competition, it usually indicates that the player's coach has a lot of faith in them to shut down the opponent's best offensive forwards, like Vlasic. Having a lot of defensive zone starts, but a low quality of comp generally means that the player has no offensive skill to speak of, and being used defensively is simply the only way to get any value out of the player, like Vandermeer. Being in the top-right of the chart usually means that the player isn't necessarily poor defensively, but that they are good offensively and the coach prefers to play them to their strength, like Burns. Being high in offensive zone starts and low in quality of competition means that the coach would like to shelter that player defensively, like Demers. Usually young players are used in these minutes.
However, I find that quality of competition isn't a great metric over a small sample size. Left Wing Lock has come out with a ton of great tools recently, and one of my favorites is the line matching tool
. Using it, you can look up which forwards or defensemen a particular player played against in a particular game, and how often within the game. If, like me, you are suspect of quality of competition at this point in a season, it doesn't hurt to look at a defenseman's opponents in their home games, ie when their coach gets to pick their matchups. Even away games' data can be interesting, as it shows an opposing coach's opinion on your player, depending on that coach's style.
Anyway, so there are a lot of ways to contextualize a defenseman's work using numbers. But while they can explain context, circumstance, and show results, only watching and determining a player's skillset can give you a richer knowledge of the player.
The most important characteristic in a good defenseman is hockey IQ: How well do they judge risks? Do they know when to jump into the play and when to stay back? Are they aware of where their teammates are? Do they have strong positioning? Do they lose their man frequently? A defenseman like Marc-Edouard Vlasic has extremely high hockey IQ, and it shows in his positioning, stickwork, and spacial awareness.
In my opinion, the second more important characteristic in a defenseman is puck-skills. It's one thing to prevent a shot, but quite another to send the puck the other way. A defenseman like Marc-Edouard Vlasic is the best example of a player who has elite hockey IQ, but very poor puck skills. He'll strip the puck from an opponent, great. Then, he'll fail to get it out of the zone or make a poor outlet pass to an opponent and they'll keep attacking the net.
Third is the physical tools, skating and size. Skating's obvious; you need to not get burned by opposing forwards on the rush, you need to be agile enough to get into position as fast as the opponent can pass the puck. Size is another obvious one; you need to win board battles, keep forwards out of your goalie's crease, etc. There are many successful defensemen who are neither speedsters nor giants, but these two characteristics really do wonders.
For every reason in this post, Alex Pietrangelo is my favorite defenseman in the NHL. He's the most intelligent defenseman out there; he's perfect positionally and seems to see what'd going to happen before it does, he can poke the puck off of any dangle. He's got amazing puck skills in all zones; he gets a hold of the puck, and he skates it out or dishes to an open teammate to the tape or makes an incredible stretch pass through the neutral zone to hit a streaking teammate for a 1vgoalie. My favorite part of watching Pietrangelo is the little dipsy-doodles he does with the puck when two forecheckers want to get the puck. He chooses one of the forecheckers, dekes around them, and skates away from the other perfectly. When he gets ahold of the puck in the defensive zone, no one's going to strip it off of him no matter what kind of traffic and chaos is in his way. He uses his reach and size well to win battles and guard a lot of open ice, and he's a very good skater for his size so he can keep up with anyone and skate out of the zone with authority. These amazing things that he can do don't even consider his blazing shot and offensive instincts. But all of these characteristics are reflected in his extremely strong underlying numbers.
Sorry that turned into quite the monster, but I'm very passionate about Alex Pietrangelo. :laugh: For my money, he's the perfect defenseman. Weber and Chara are up there, and Karlsson is actually capable of proving the old adage "offense is the best defense" simply because the puck is always in the offensive zone when he's on the ice, because he's so good.