A few days ago, there was a fairly drawn out debate over whether or not Luke Schenn is a superior defender to Dion Phaneuf. Some would argue Phaneuf is "easily" the superior blue liner, and I feel it's quite easy to concede that fact on an offensive basis, at least superficially. Phaneuf is generally regarded as one of the top offensive defenders in the NHL and has been for all intents and purposes since his rookie season.

Defensively though, I am not entirely certain whether this is entirely justifiable.  Earlier in the summer, David Johnson at Puckosphere.com threw some cold water on the idea that Schenn was a "capable" defender, but there were some issues I had with his analysis.  Largely the fact that he ignored goaltending effects and concluded Schenn is inferior as a result of the number of goals allowed with him on the ice.

More recently, there have been repeated suggestions that Phaneuf's higher Corsi REL QoC and lower Corsi REL QoT values indicate that he was playing with worse line mates against tougher competition (ironically the same people may have argued that Corsi is a "horrible stat"... let me know if you can figure that one out).

So... let's try to sift through the chaff in all of this discussion and in a more concise fashion describe what we know about the two d-men from last season.

1. Yes, Luke Schenn faced easier competition from a Corsi REL standpoint. Phaneuf's Corsi REL QoC was 0.724, which is still pretty far from the top end of D men in the NHL. For instance, Nik Lidstrom's Corsi REL QoC was 1.807, and Marc Staal's was 1.602. Phaneuf's number is actually lower than Drew Doughty and Travis Hamonic (a rookie with the Isles this past season), so while it's tougher than Schenn's number, it's not astronomically difficult. Phaneuf ranked 39th in the NHL in Corsi REL QoC last year amongst D men who played 60+ games. Luke Schenn's ranking was 82nd in the NHL at 0.392.

Here's where it gets interesting - many Leaf fans will tell you Francois Beauchemin is a top notch defender, and the Leafs suffered in his absence. Beauchemin finished this past season ranked 81st, immediately ahead of Schenn amongst D men with 60+ games of play, with a Corsi REL QoC of 0.406. So apparently Beauchemin is a top shut down guy, and he faces very similar competition to Schenn.

Other big name D men with EASIER Corsi REL QoC loads than Schenn include Brent Burns (0.378), Tyler Myers (0.373), Jordan Leopold (0.341), Fedor Tyutin (0.331), Scott Hannan (0.285), Dennis Seidenberg (0.276), Niklas Kronwall (0.276), Ron Hainsey (0.243), Johnny Oduya (0.233), Mark Gioradano (0.172), Anton Volchenkov (0.140), Andrew Ference (0.031), Pavel Kubina (-0.030).

Let's put it another way, there were 173 D men that played over 60 games in the NHL last season, and Schenn was in the top half in terms of competition toughness from a Corsi perspective.  His number was the 2nd most difficult on the Leafs by the end of the year (excluding Aulie who played 40 games).  This makes it sort of difficult to argue that he was horribly sheltered.  The average Corsi REL QoC for those 173 D men was 0.353, so Schenn's opposition was at the least, slightly more difficult than average.

Phaneuf's defensive opposition was certainly more difficult though, as his opposition falls in the 78th percentile for the group.  All of this being said, if Corsi isn't a great measure of play, then arguing that Phaneuf's Corsi REL QoC is an indicator of his opposition seems a tad misguided.

2. If we look at defensive zone starts vs. offensive zone starts at ES, then we could see that Schenn was on the ice for 438 defensive zone faceoffs (5.3 per game), while Phaneuf was on the ice for 363 (5.5 per game).  Of course that changes a bit when you factor in special teams time.  Schenn was on the ice for an additional 221 defensive zone faceoffs on the PK, while Phaneuf saw 89 more, while on the PP Schenn saw 9 D zone starts, and Phaneuf saw 13.

That works out to 668 D zone faceoffs for Schenn (8.15 per game) in comparison to 465 for Phaneuf (7.05 per game).  I guess that might be an indicator of who the coaching staff felt was more reliable in the Leafs own end.

3. Schenn played with superior players... at least... from a Corsi perspective.  Again, the Corsi issue seems to rear it's head in this discussion.  If you think it's a valid assessment of possession, then the numbers indicate Schenn's linemates tended to do a better job of keeping the puck in their possession than Phaneuf's did.  This to the tune of 0.732 for Schenn vs. 0.010 for Phaneuf.  Personally I am in agreement that this would be a boost to Schenn's play, and a detriment to Phaneuf's.

Of course, what is sort of implicit here is the following - Schenn tended to play against opposition players that weren't as good at maintaining possession as those Phaneuf played against... and the guys who were on the ice with Schenn tended to do well at holding on to it.  Logical corollary much?  My line mates are most likely playing against players who aren't as skilled at maintaining possession, so they end up with the puck more.  Your line mates are likely playing against players who ARE skilled at maintaining possession, so they end up with the puck less.

The end result of this out look is that Schenn's linemates likely benefitted (as Schenn did) from a slightly lower level of competition - which in turn inflates their possession numbers a bit.  Phaneuf likely suffers from the opposite situation.  If his opposition is generally more skilled at maintaining control of the puck, then it stands to reason that he and his line mates aren't that likely to have it most of the time.

Whether or not you feel these values are mutually exclusive, I can't imagine a situation where the one does not impact upon the other.  It is a far distance from explaining things completely, but it does have an impact.

4. Schenn's Corsi ON number of -4.15 is a fair bit higher than Phaneuf's -6.20... but they're both on the negative side of the ledger. Again, here's where a comparison to Beauchemin is enlightening. Beauchemin had a negative value for his Corsi ON of -4.35 (below Schenn despite having virtually the same competition from a Corsi perspective). Other top end D men with negative Corsi ON values include Brent Burns (-4.08), Trevor Daley (-6.69), Chris Phillips (-7.22), Dan Girardi (-7.65), Mattias Ohlund (-7.96), etc. End result of this is, Schenn is surrendering more shots on the ice than he's taking, but so is Phaneuf, and Phaneuf's surrendering more.

5. Luke Schenn played in front of inferior goaltending last season on the whole. He was on the ice for all 82 games last season, and Jonas Gustavsson and JS Giguere were in net for a lot of those early on in the year.

The ES SV% for Schenn this year was .916, while the ES SV% for Dion Phaneuf was .921. That largely indicates the distinction that seeing ice time largely in front of James Reimer had on Phaneuf's year. Despite David Johnson's arguments to the contrary, I think it's very unlikely that Phaneuf OR Schenn had a significant impact on the SV% of the goalies playing behind them over the course of the season. Since this is largely a factor of luck, then it is fair to argue that if Schenn and Phaneuf had played in front of IDENTICAL goaltending, then Schenn would have been on the ice for fewer GA/60 than Phaneuf.

As it currently stands, Phaneuf was on the ice for 2.49 GA/60 at ES, while Schenn was on the ice for 2.64 GA/60.  The Leafs fired more shots on goal with Schenn on the ice at ES, and surrendered more shots against with Phaneuf on the ice.  Thus if their SV% values had been identical, Phaneuf would have been on the ice for more ES goals against for a given amount of ES ice time.

6. Dion Phaneuf surrendered more high risk scoring chances during Even Strength play than Luke Schenn according to the scoring chance data from this past season recorded tirelessly by Slava Duris.  More specifically for every 60 minutes of ES ice time, Phaneuf surrendered 0.38 Traffic Chances, while Schenn surrendered 0.28, and overall Phaneuf surrendered 2.38 "net presence" chances, while Schenn allowed 1.96.

While it could be argued that Tomas Kaberle strongly influenced Schenn's numbers, it does seem reasonable to point out that Schenn played February, March, and part of April without the help of Kaberle as his blue line partner. If we add Beauchemin's play into the mix, it should be pointed out that he was allowing 2.64 "net presence" chances against per game with the Leafs prior to his exit. That isn't flattering in the least.

7. From a DELTA SOT perspective (which is a plus / minus stat that incorporates shot location as a proxy for scoring chance quality) Schenn's mid-March score was +3.8 at ES and the best amongst the Leafs D, while Phaneuf's was -1.9.  Even on the PP, Schenn's DELTA SOT score was higher than Phaneuf's (-0.9 vs. -1.3).  These results indicate that Phaneuf tends to fire more shots from bad scoring locations (which makes sense given his propensity to blast away from the point), and that he also has a knack for surrendering shots from unfortunate locales (which aligns well with the scoring chance data measured in section 6 above).

Schenn on the other hand seems to do a reasonable job of helping the puck move up to the forwards in a solid position to shoot and score (hence all those assists and decent Corsi results),  and also reduce the number of chances being taken in the slot against his team (hence his superior values for net presence chances against).

8. Luke Schenn hits more, and blocks more shots than Dion Phaneuf.  I know, I've read all the debate over the usage of real time statistics kept by the NHL.  They're poorly logged by NHL statisticians, and as a result of variation in venue, they make for crappy comparisons.  Luckily for us, Luke Schenn and Dion Phaneuf play on the same team, and thus were exposed to the same score keepers in the same games.  Schenn did play in 16 more games, but on a per game basis, his hit and blocked shot numbers are quite a bit above Phaneuf's.

Schenn had 251 hits, and blocked 168 shots.  That works out to 3.06 hits per game, and 2.55 blocked shots per game.  Phaneuf in contrast had 186 hits, and 121 blocked shots.  That works out to 2.81 hits and 1.83 blocked shots per game.  This MIGHT have something to do with why the Leafs surrender more shots with Phaneuf on the ice.

At even strength, the Leafs as a team block slightly more shots with Phaneuf on the ice, and the opposition misses the net a bit more often.  This of course contributes to Phaneuf's inferior Corsi number.  The team is surrendering more opportunities in general, but again that goes hand in hand with having the puck less.  Irrespective of that fact, Phaneuf himself is not doing a lot of the blocking that seems to lead to this result.

Conclusion

I'm open to further debate on this point, and I'll concede that Phaneuf faced some solid players when he was on the ice.  He was the Leafs go-to guy on the power play, and he spent more time on the ice when he was healthy than any other Leafs blue liner.  But defensively, on the PK, the Leafs coaching staff obviously relied upon Luke Schenn.  At even strength, Schenn was more offensively productive as well, and while much of that may have been luck of the draw, the fact remains that he did his job adequately from the offensive end when he was given the opportunity.

Hopefully this coming season sees Schenn mature further (once he's under contract of course), and we can take solace in the fact that the increased depth on the Leafs blue line means we have more to look forward to if either or both of these players make sizable strides defensively.  I'm sure James Reimer hopes so.