There is nothing perhaps more encouraging to fans of struggling teams than to see a rookie D-Man come up and put up big numbers right out of the gate.  I speak of course, not just about goals and assists – in this case I refer to good possession #s (Corsi, Fenwick, and the relative versions thereabout).  Fans of the Oilers (Marincin), Leafs (Rielly), Isles (de Haan, Donovan), etc, all seem to have higher hopes than they might’ve otherwise due to how well their rookie D has performed.  After all, a top pair D Man (under control for cheap for years to come) can have such a great impact and they are extremely hard to find on the free market (or trade market).

But can these standout rookie D keep up their great performances?  After all, we always hear about the so-called “sophomore slump” and it’s not like players disappointing after great rookie years is that uncommon.  How certain can we be about the futures of rookie D-Men who come up and right away show strong possession #s?  Let’s see how similar rookie D the last few years did.

I went back and gathered all rookie D Men from 2010-2011 to 2012-13 who played 40 Games or more (to get a decent sample size).  I then took the guys who managed a +2% Relative Corsi or better and put them on my list.  The 2% requirement is obviously somewhat arbitrary, but +2% or better is a really good # for any player (and better than that definitely is) and I like to think that type of # is a good proxy for where we can begin to say rookies are giving their team’s fans a lot of hope.*

*Alternatively, it’s the range around where Morgan Rielly is this past season, which is what spurred this investigation on.

This gave me 19 rookie D Men who pulled the feat – 5 from the lockout season (out of 7 qualifying defensemen), 3 from 11-12, and 11 from 10-11.  2011-2012 seems to have been a particularly bad year for rookie D-Men – we had 11 in 13-14 and probably would’ve had a similar # if the lockout had gone 82 games.  How’d they do in the seasons thereafter?  Lets’ look:

These are the 19 rookies I mentioned before. The ones in Green followed up their solid rookie seasons with clearly positive seasons thereafter. The ones in red followed them up with more problematic possession seasons, to be fair (“DNQ” means “Did Not Qualify” for the 40 GP cutoff in future seasons). The ones in purple had some mixed results thereafter. As you can see, the 19 players settle nearly evenly into the three categories – 7 continued to post clear positive play, 6 put up mixed performance, and 6 were poor in possession to total busts for whatever reason.

Now some of this is probably due to context. Most of the rookies on this list had pretty easy zone starts and minutes during their rookie seasons and some of that went away in years thereafter.  And of course relative stats are comparing you to your teammates, so better teammates could also result in the worse #s.

That said, the overall conclusion is still pretty clear: 1 season of good relative corsi #s for a rookie D Man doesn’t mean you’ve clearly found the next great defender.  It’s a better measure than +/-, but it isn’t ironclad in reliability as a metric – one season’s sample just isn’t big enough for this.

In other words, don’t be too quick to conclude a great season for a rookie D means that they should be untouchable – they’re still far from a sure thing.