Comments on: The Methodology Behind the SI Predictions

By: Analytics predicts the 2016 NHL playoffs and Cup winner | | Geoponet Sports

Wed, 13 Apr 2016 22:23:33 +0000

[…] Before getting to the fun, a word about our model. We looked at dozens of regular season statistics and the outcome of every playoff series since 2008 (a total of 120). After a lot of mixing and matching, we settled on a technique called factor analysis, which allowed us to take the 12 best variables and combine them in a single model (for those who like math, it’s the same methodology as we used last year—but with different numbers—you can read more about it here. […]

By: Scott Kalina

Scott Kalina — Sat, 06 Jun 2015 14:22:00 +0000

Thank you!

By: Ian Cooper

Ian Cooper — Sat, 06 Jun 2015 03:21:49 +0000

Thanks for listening Scott! Strength of schedule does indirectly find its way into our model by way of the Simple Rating System (SRS) used on hockey-reference.com (http://www.hockey-reference.com/leagues/NHL_2015.html) which was one of the variables we included.

That measure takes a team's goal differential and either gives it a bump or a haircut based on the goal differential of each of its opponents. The math is basically a massive system of equations, but the basic idea is if you beat the Leafs by 3 goals, and on average they lose by 2.5, your SRS would be 0.5 even though your goal differential might look far more impressive. Because every team's SRS is dependent on that of every other team, the math gets more complicated than that, but that's the basic idea. So, for example, Tampa had a goal differential of +51 (0.62 per game), which looks a lot better than Chicago's +40 (0.49 per game), but in fact the teams were a lot closer because of strength of schedule, giving Chicago an SRS of 0.51 vs. Tampa's 0.57. Tampa still gets the edge there, but you're correct - the margin shrinks once you take into account strength of schedule.

Anything can happen in a playoff series, but we think odds are very high that this one's going to be close!

By: Scott Kalina

Scott Kalina — Fri, 05 Jun 2015 23:19:01 +0000

Enjoyed you guys on NHL Radio this morning. Does your methodology include strength of schedule? In the SCF, for instance, the Blackhawks regular season record & stats is based on playing all the teams in the Central 5 times, the weakest being COL with 90 pts. However, TB played a total of 10 games against TOR & BUF. It would seem CHI should get some type of bonus for playing STL, NSH, MIN, WPG multiple times.

By: Phil Curry

Phil Curry — Thu, 28 May 2015 22:27:24 +0000

The "luck" variable is definitely capturing a bunch of things. Exactly what is worth more investigation, but the Ducks are definitely different from other teams over the past 7 post-seasons who won a lot of one-goal games. It has been a heck of a series, though. I look forward to game 7 for sure!

By: Shawn Martin

Shawn Martin — Thu, 28 May 2015 19:24:32 +0000

How the puck luck variable is determined, it is conceivable that it contains, at least for some teams, things other than puck luck. For instance, teams that have strong starts, get the lead but then get fatigued or get too "comfortable" and allow late goals, resulting 1 goal wins. I think some of these may not occur as much in the playoffs since the cup is in sight and teams bring their A-game which may be the case with the ducks. I didn't watch them play very much in the season so I don't know for sure, but i think their puck luck variable is correlated to some "bad habits" which they have corrected. It might be interesting to calculate puck luck using the same method, but only games where the final goal is the game winning goal (if that data is easily compiled), and maybe Anaheim's probability will increase. Anyways I guess we'll see if your predictions are right on Saturday, I hope they are. Go Hawks

By: Ian Cooper

Ian Cooper — Thu, 23 Apr 2015 03:09:42 +0000

I'm definitely being a little tongue in cheek by fixating on this, and either Phil (Curry not Kessel) has a bad short term memory or didn't read the piece too closely. ; ) But at the time I imagined the Pens giving up one of their young D (Maatta being the most obvious since he was out for the season) and presumably some first round picks beyond this year's draft. And while capgeek was no longer available to give precise information, based on what I read elsewhere it looked like dumping a 35 year old Rob Scuderi would have gotten them awfully close on cap space. Of course to be fair I didn't imagine their D would be further decimated. Nevertheless, I remain committed to the idea that Kessel would be a fantastic Penguin; whereas, he'll just languish and be abused in Toronto well into his 30s if he stays here. So maybe that's an offseason move. You can read the full piece below if you'd like...

https://www.bsports.com/statsinsights/nhl/penguins-need-phil-kessel#.VThhkWRViko

By: Phil Curry

Phil Curry — Wed, 15 Apr 2015 20:25:49 +0000

Hi Henry, It's good to hear from you again, and thanks for the kind words. Honestly, I don't have a great answer to that question. We should have done that, as I suspect that you're totally right. Ah well, we'll have to remember that for next year! Hopefully we haven't lost too much predictive power with that omission, but I have no doubt it would have helped. Phil

By: Henry Bee

Henry Bee — Wed, 15 Apr 2015 20:20:21 +0000

Phil, we talked a while back about your study of the contract year. I see you continue to do great work. I'm wondering why you didn't also include second half CF%, scoring chance for%, as well as post trade deadline CF% etc. I believe these sub-periods would provide additional explanatory power over the full season or last 10 games.

By: Phil Curry

Phil Curry — Wed, 15 Apr 2015 20:01:38 +0000

Yeah, Ian somehow got fixated on that idea and seems to be having difficulty letting it go. I'm not really sure how he thought that could happen. I'll see if I can get him to give you (and the rest of us!) an answer. He's a shifty lawyer, though - not always easy to pin down! Phil