After looking a bit deeper into what got these guys into Randy Carlyle's good books while John-Michael Liles, who hasn't played all that bad, sits on the sideline I discovered that both Holzer and Kostka are right-handed.
While this doesn't seem to be earth-shattering news, of the Leafs NHL defensemen, only Holzer, Kostka, Cody Franson, and Mike Komisarek are right handed, and Randy Carlyle has almost exclusively rotated these four defensemen, along with the left-handed Liles, through the 3 right-side positions this year. Since Holzer's call-up, Carlyle has exclusively used Holzer, Kostka and Franson on the right side. (Prior to this Liles spent about two weeks on his off-side playing with Carl Gunnarsson)
It is also interesting to note that Carlyle dressed 3 right-handed defensemen in the Season Opener against Montreal, which may again suggest that his ideal situation preference is to keep his defensemen on their “natural” side. (As an aside, in the system Jesse Blacker, Stuart Percy, and Tom Nilsson are Right-handed, so if you're Randy Carlyle, the future looks somewhat bright in this regard)
This “natural-side” philosophy explains why Liles was the odd man out when Gunnarsson returned to the line-up last week rather than pulling the less established Kostka or Holzer out. Although Liles has often played on his off side throughout his career, when Gunnarsson returned to the line-up he was playing on the left side paired with Mike Kostka and Carlyle certainly wouldn't remove top-pairing-Phaneuf or plus-fifteen-Mark Fraser who has developed a nice chemistry with Cody Franson. One can only guess, but it appears that Randy Carlyle prefers the play of Kostka, Holzer and Franson on their natural right side to that of Liles on his off-side, and the play of Phaneuf, Gunnarsson and Fraser on their natural left side to that of Liles. There's also the issue of Liles' size, which likely plays into the decision, as Carlyle seems to prefer big strong defensemen to smaller.
From what I have found, notable names in the NHL that stick out among right handed d-men include Dustin Byfuglien, Zach Bogosian, Johnny Boychuk, Dougie Hamilton (ouch! It still hurts to say his name), Tyler Myers, Dennis Wideman, Brent Seabrook, James Wisniewski, Justin Schultz and Erik Gudbranson, Shea Weber, Kevin Bieksa, Drew Doughty, P.K. Subban, Daniel Girardi, Erik Karlsson, Luke Schenn, Chris Pronger, Kris Letang, Dan Boyle, Alex Pietrangelo, Kevin Shattenkirk, Mike Green. Notable retired right-handed Dmen include Rob Blake, Sergei Zubov and Brian Rafalski to name a few.
Interestingly enough, of the 10 strongest defensive teams this year with regards to GA/G as of Saturday Morning, the only team missing a right-handed d-man on their top pairing is the Montreal Canadiens. (The Leafs were tied with NJD for 10th at 2.50 GA/G) Montreal's top pair consists of Andrei Markov and Alexei Emelin, but when Carey Price is in net, you have a bit of an unfair advantage defensively. The hot starting Anaheim Ducks (who rank 14th in GA/G) are also notably completely without a right-handed defenseman in their top 6.
Now there are many other teams with Right-handed top-pairing defensemen who aren't in the top ten, so obviously team defensive system and player skill play a major factor in this, not to mention goaltending. Regardless it is quite apparent that given the choice, NHL coaches will always try to play a left and a right-handed defenseman as a pairing. The fact that I could find no right-right pairings throughout my research further supports this theory.
Personally, in an ideal world, I would tend to favour having Phaneuf play his off-side with Gunnarsson rather than playing with the inexperienced Holzer or Kostka. To this point after 22 games Phaneuf is -7, while all of last year (including the whole 18 wheeler-cliff incident) Phaneuf was -10 against similar quality of competition. Even back during his 'glory days' when he was an all-star in Calgary, he played with the left handed Robyn Regehr. Where this option get's dicey however, is with Gunnarsson's play so far this year. He's been far from the solid Carl Gunnarsson we've seen over the past few years. This is most likely due to his nagging hip injury, an injury that is expected to bother him and keep him at less than 100% for the rest of the year. So, until he can truly take care of it in the off season this may not be an option.
Given the Gunnarsson situation and the Leafs' significant improvement in the goals against column, I really can't argue too much with Carlyle's decisions in his defensive pairings. (Although an argument could be made for removing Carl Gunnarsson altogether from the line-up until his hip is truly healed) Even if Holzer isn't truly ready for top-pairing NHL duty yet, as long as the team is winning and in a playoff position the experience can't hurt. Besides, it's not like the Leafs have someone available who is far and away outplaying him on the right side.
As another little aside, given the seeming importance of handedness and the preference most defensemen have for one side or the other, it has always seemed odd to me that defensemen are not listed as left defense and right defense in the same way left wingers and right wingers are identified. Sure, there are many defensemen that will play either side, but the same is true of many wingers.
What to do next:
Given the Leafs depth on the left side a trade does seem likely. The question then becomes, who should they trade and what could they get return. Personally I like the fit of Liles to Detroit, although I don't know what would be available in return. What would you Do?
Leafs Defensive Depth Chart (not necessarily in order):
Ranger (if he were to sign)
Here are a couple of links to articles that I found during my research that look into this a bit further:
This article discusses a right-handed d-man the leafs gave up, Luke Schenn, and the question of importance of handedness when it comes to defensemen.
This article discusses possible reasons why there is such a disparity in right and left shooting defensemen:
And finally, the 3rd post down gives a great explanation of why there are so few right shooting defensemen, from what I've read these numbers correspond perfectly with the actual figures on right and left shooting players.
I tried to reply to the first comment in the comments section but it didn't work...hmm. So I'll just address it here:
I think my use of plus/minus here is acceptable because I'm comparing Dion Phaneuf of last year to this year with similar quality of competition and stronger attributing factors this year. (i.e. better goaltending and team defensive system) If anything his +/- should be better this year, not worse.
Regardless, that was only a minor component of my argument.
While it is possible that the other defensemen are simply just better than Liles, or even just better fits in Carlyle's system due to size and defensive ability, I still think the right/left thing is an interesting concept.
Maybe I overreached a bit, but if it didn't matter at all you would have defensemen playing on their off side all the time - which isn't the case. If available (look through most NHL team's line-ups) there is a right and left handed defenseman paired together.
While a significant skill differential would trump handedness, given the choice of two equally skilled defensemen the coach will always go with the natural side defenseman.
Anyone using plus/minus in their analysis is shooting themselves in the foot. Youre reading too much into it besides, Kostka is a good defense,en: mobile, great pass, can play PK or PP and Liles is too one dimensional. Kostka blocks shots and is just better all around than Liles. Also, with Gunnerson, Kostka, Franson, and Phanuef, all the things that Lies is good at are duplicated and so unnecssary. Also, he has no size and is not "difficulut to play against". The whole right/left thing doesnt matter. Its whose better.
With saying all the things Liles is good at are duplicated, would you apply the same principle for Jake Gardiner and Morgan Reilly?