Photo by “Resolute”, via Wikimedia Commons; altered by author

Having now looked at the overall effect a coaching change might have on a team, and identified some outstanding examples where a coaching change had a drastic impact on a team, it’s now time to shift over to some juicier matters. For the most part, I don’t think one coaching change is necessarily sufficient to say a coach is good or bad; there is a possibility the previous coach was just that bad. But if the coach returns the same signal a couple of times or more, you are probably getting closer to a true reading on what they might bring to the table.

Across the 140 or so coaching changes these last 60 years where both coaches led the team 20+ games, there were 69 coaches who were a part of that change twice or more (which, to me, is quite a remarkable number). The full list, followed by an explanation of the measures:

Some explanation: the values with the headings starting with “Avg” are the average change in 2pS% (an historical possession metric, explained here), in 2pSF/60 (designated “Off”; shots-for per 60, using the rates up through the 2nd period rather than full-time), and 2pSA/60 (designated “Def”; rest same as with SF only working with shots-against). The perspective is from that of the coach – so, if Tom Renney was replaced and shots-for went down, he would be seen as a positive influence on shots, and if Renney replaced someone and shots-for went down, he would be seen as a negative influence. The shorter explanation is that this is the presumable impact on those metrics these coaches would have if you put them behind the bench. I included the standard deviation for each average to inform whether the average involved wide or narrow disparity in the data used for the average.

Overall, if the standard deviation exceeds the average value, then there’s a greater likelihood the reading is a) a bit too noisy for conclusion, and b) suggesting a coach’s average could very well be a mirage.

Anything jump out at you? Well, to me, I feel we once again see an evaluative rule play out here: that there are a limited number of people who give you a clear signal, and the rest should receive the benefit of the doubt and be left to the inconsistent noise. That certainly writes off some pretty big names, though, doesn’t it? Scotty Bowman, Roger Neilson, Ken Hitchcock, Pat Quinn…there’s a number of coaches here you were sure would deliver, but really provided a mixed bag. Truth be told, I think Bowman gets kind of under-served here, as two of the changes involved his messy Buffalo tenure. When it was between he and Al Arbour with St. Louis in 1970-71, it was Bowman who oversaw a 0.7% uptick in possession.

On the negative end, there sure is no saving Glen Hanlon, who might have defended himself as the heir to the Jagr disaster in Washington, but had little excuse once Ovechkin, Semin, Mike Green, and Nicklas Backstrom were running on all cylinders. Therrien I’ve already covered, but how consistent is Mike Keenan? He helmed some fantastic Flyers teams in the 1980s, but by the 1990s the Iron Mike act was wearing thin on players and front offices alike. Punch Imlach is also an interesting one, an unassailable character in some arenas (including The Hall), his tally includes taking the reins in Toronto from a legend who is not in the Hall, Billy Reay, in 1958. Reay, you’ll notice, is much higher on the list above.

On the positive end, we have some clearer signals (keep in mind, per my first post on this topic, that the average expected 2pS% shift is +0.66%). Jim Schoenfeld is the undisputed star, an appropriate label for the man who once cut a vinyl record with his karaoke-quality vocals, as he made significant impacts in all his stops in Buffalo, New Jersey, and Washington (the latter mentioned in my previous post). Lorne Molleken is likely a surprise, but Bruce Boudreau definitely is not – nor is Darryl Sutter. Craig Patrick and John Tortorella are certainly the most intriguing…my guess is Torts benefits from two instances of mediocre previous coaching, but Patrick has given us four instances of positive replacement work, in 1980 and 1985 for the Rangers’ Fred Shero and Herb Brooks, then in 1989 and 1997 for the Pens’ Gene Ubriaco and Eddie Johnston. The latter two were at the same time Patrick was Pittsburgh’s GM. Nobody can take away Patrick’s Cup championships with the Pens, but he sure received (and, to some degree, earned) a heap of criticism as the wheels fell off the wagon in the early 2000s. These days, Patrick is haunting the hallways of the Buffalo Sabres organization as a Special Advisor while Schoenfeld is the Rangers’ Assistant GM, and Torts is probably a lumberjack with Dexter Morgan or something.

Bringing this little series to a close, I’m reminded of something Vic Ferrari mentioned in Elliotte Friedman’s great unveiling of Ferrari’s persona.* Vic noted that NHL coaches are “smart guys” who “have a hell of a grasp of who is bringing what to their team,” and I generally agree with that for the same reasons I agree with Tom Awad’s assertion that time on-ice can tell you a lot about who are the “good players.” I think this is generally true, and I very much believe that there are coaches out there that couldn’t care a lick for complicated metrics yet still have an eye for talent and what works. That being said, there are still boobs in the bunch, and it’s important to find ways to identify and avoid them; looking at coaching change history is one way you could accomplish that.

* I’m not lost on the irony that I mention Vic, who was originally inspired by Roger Neilson, in the same post that suggests Neilson didn’t necessarily have a positive impact on his teams.