Followup on Rielly’s Save Percentage

The other day I wrote about Rielly and his on-ice save percentage. A brief twitter discussion with Tyler Dellow occurred which ended with Dellow asking me to explain how Rielly went from -0.9 Sv% Rel in 2015-16 to -2.8 Sv% Rel in 2016-17 while playing similar shut down roles in both seasons.   He was -.009 relative to team in 15-16 playing the same “shut down” workload as most of…

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Rielly, Gardiner, the Rookies and Save Percentage

Yesterday Tyler Dellow wrote about Morgan Rielly’s poor on-ice save percentage over the past two seasons. While it is an interesting read, the hypothesis at the end of the article left me wondering why it wasn’t explored more. The article starts out wondering if shift start location may be a factor at play in Rielly’s poor on-ice save percentage. Dellow noted that generally defensive zone shift starts result in higher…

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Who should Leafs target to improve Defense?

Earlier this week James Mirtle wrote about whether the Leafs should trade some of the future to improve the Leafs defense now (requires subscription). Specifically he identified the need for a top pairing right side defenseman to play with Gardiner. The second pairing would be Rielly with Zaitsev and the proposed third pairing would be Dermott with Carrick. For that top pairing right side defenseman Mirtle identified 7 potential targets: Justin Faulk,…

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Summer Project: Stat site rebuild…

The core of my code to generate my stats used at stats.hockeyanalysis.com and puckalytics.com is nearly 10 years old. Since then the code has been modified, extended, and optimized but has now reached the point where I am thinking it has seen its best days and I need to do a complete re-write to get to implement some of the new features I would like. My code was written to work…

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Dissent and uncertainty…

So, it seems Hockey Graphs doesn’t like dissent. I tried to post a response in the comments to Matt Cane’s defense of WAR to respond to the latest Hockey Graphs attack (though a far more substantiated critique than most other Hockey Graphs writers as I would expect from Matt). Of course the Hockey Graphs policy is to stomp out and censor critique and discussion so it seems it didn’t pass…

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How good is Nick Foligno

GAR suggest Nick Foligno is quite good. Secret Stars: How the underrated Nick Foligno and Brandon Saad are bringing the Blue Jackets to new heights. https://t.co/aqH7XjHw80 pic.twitter.com/1g9PDKpCSh — dom (@domluszczyszyn) March 30, 2017 Some might even call him “Secret Star” (see above) that the rest of the NHL hasn’t caught on to. Anyone who shares the ice with Foligno and Saad plays and looks better, and it’s for that reason…

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GAR, What is it Good For??

So, this whole heated debate started when I criticized using GAR to draw conclusions about hockey players. Let’s use this metric that rates Mathieu Perreault (11g, 38pts) ahead of Scheifele (29g, 77pts) to show why Foligno and Saad are so good. https://t.co/lFJdXD90Sy — David Johnson (@hockeyanalysis) March 30, 2017 What has gotten lost in this whole debate and group attacks from the Hockey Graphs writers is that I think GAR…

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GAR and dealing with Critique in Hockey Analytics

The other day I caused a bit of a stir on twitter when I critiqued this article by Dom Luszczyszyn at The Athletic (paywall required unfortunately). My critique went like this: Secret Stars: How the underrated Nick Foligno and Brandon Saad are bringing the Blue Jackets to new heights. https://t.co/aqH7XjHw80 pic.twitter.com/1g9PDKpCSh — dom 🤡 (@domluszczyszyn) March 30, 2017   I get why people love WAR/GAR stats but if you rate Perreault >…

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Binning to Overcome Noisy Data

Apparently hockey analytics hates “binning” and ‘petbugs’ is the latest to write about it today over at Hockey Graphs. There are reasons not to use binning, however binning can help overcome noise in observed data. As this is a hockey blog lets use shooting percentage as an example. In hockey, shooting percentage observations show a lot of randomness in them due to the small sample sizes we are dealing with. Here…

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Rielly and Quality of Competition

The issue of the importance of quality of competition is a hotly debated topic in hockey analytics. On the one hand it is easy to believe that players that play shut down roles against the opposing teams top players are likely to have their statistics negatively impacted. On the other hand, hockey analytics hasn’t been able confirm that is true as most analysis suggests the impact of quality of competition is…

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