An Introduction To New Tracking Technology

The first significant breakthrough in hockey analytics occurred in the mid-2000’s when analysts discovered the importance of Corsi in describing and predicting future success. Since that time, we’ve seen the creation of expected goals, WAR models, and more. Many have cited that the next big breakthrough in hockey analytics will come once the NHL is able to provide tracking data. We’ve already seen some of the incredible applications of the MLB’s Statcast data and the NBA’s SportVu data. Unfortunately, the NHL has no immediate plans to publicly provide this data and as such, many analysts have decided to manually obtain the data.

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Hockey-Graphs Podcast Episode 9: Erik Karlsson and Market Value

Chris Watkins joined Adam Stringham to discuss some of his new work and Erik Karlsson’s recent comments. Is the NHL entering a new age of superstar transition? Will the leagues best players start jumping around in free agency? Any comments are appreciated, the goal is to produce a podcast that people want to hear. Please subscribe to the podcast on iTunes!

Estimating Shot Assist Quantities for Skaters

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Hockey fans and analysts have always appreciated the importance of passing. But until the passing project led by Ryan Stimson, we couldn’t quantify that importance. His work supported by a team of volunteers and other analysts has established that the passing sequence prior to a shot is a significant predictor of the likelihood of the shot becoming a goal. His work also showed that measuring shots and shot assists combined as shot contributions is a better predictor of future performance for both players and teams than shots alone.

Knowing that, the logical next step is to use passing data in analysis whenever possible. Unfortunately, the NHL does not provide passing data so it must be manually tracked by people like Corey Sznajder. Corey’s work is invaluable and I encourage you to support him but he’s only one person.

This article attempts to estimate a player’s quantity of shot assists in a given sample using publicly available data to help fill in gaps where tracked data doesn’t exist.

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Behind the Numbers: What Makes a Stat Good

By MithrandirMage [CC BY-SA 3.0], via Wikimedia Commons

Every once-in-a-while I will rant on the concepts and ideas behind what numbers suggest in a series called Behind the Numbers, as a tip of the hat to the website that brought me into hockey analytics: Behind the Net.

Hey! Remember me?

I work full-time for (slash help run) HockeyData, a data tracking and analysis company. Because of this conflict of interest, it limits what I can and cannot talk about. The good news is I can still talk generalities, the basics behind analytical thinking in hockey, and other peoples’ good work, which fits my Behind the Numbers series.

Why have there been so few updates then? Been busy (…lazy).

One generality I’d like to rant about is how we look at and evaluate statistics and models: how meaningful different numbers are and why we view them that way.
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Hockey Analytics Data Sprint Wrap Up

On Saturday, November 4th, we hosted the first ever Hockey Graphs Analytics Data Sprint.  The idea was teams had 6 hours to take raw data and do something interesting with it as a trial for the Vancouver Hockey Analytics Conference. Local teams met up at La Casita here in Vancouver, but we also had online participants as well.

Thanks to all of the people who helped put it together, and thank you to all those who participated, especially those who travelled from as far away as New York.

In this post we link to the finished results and you can see the winners.  Their work is in a github repo which you can use for your own data analysis!

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Save The Date: VanHAC 2018!

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Hockey-Graphs is once again excited to be co-hosting the Vancouver Hockey Analytics Conference for its third year! We will be working with the Vancouver Canucks, Simon Fraser University and the great team at CanucksArmy.com.

This year we’ll have a 3 day conference, with 2 days of talks, tutorials, keynotes and great discussions. There will also be plenty of social events throughout the weekend.

All knowledge levels are welcome.  If you are interested, you are more than welcome! Nobody will be turned away, everyone is encouraged to attend.

Date: March 2nd to 4th, 2018

Location: Downtown Vancouver, Canada

Website: https://hockey-graphs.com/events/vanhac18/

The Call for Presentations is currently open with a deadline of January 8th, 2018.  See the website for more details or go here to submit your talk. 

Registration has yet to open as we tabulate the final costs to host the venue, among other factors. Check back here or on Twitter, or add yourself to our mailing list, for more information on when it will open. (Note: Expect participants to be capped at around ~175 people.)

Watch the VanHAC page for updates as they are released!

Hockey-Graphs Podcast Episode 8: Market Efficiency and Diminishing returns

Shawn Ferris joined Adam Stringham to discuss some of his work over the last year including: his piece on whether shot parity is increasing, a look at how teams relying on high percentage changes are less consistent in their expected goal output and some of his upcoming works. Any comments are appreciated, the goal is to produce a podcast that people want to hear. Please subscribe to the podcast on iTunes!

#RITHAC 2017 Slides & Video

Yesterday, the third annual Rochester Institute of Technology Hockey Analytics Conference was held. Below are links to the slides for each presenter, as well as links to a stream of the morning and afternoon sessions. Please refer to this post for the time of each person’s talk or panel. More detailed recaps are undoubtedly coming from people, so this is simple a reference for streams and slides for those that missed the event or would like to revisit certain talks.

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About that Flyers challenge last night…

Embed from Getty Images

Last night Dave Hakstol and the Flyers were the first team to get burned by the NHL’s new offside challenge rule. With a one-goal lead over Nashville and just 2:41 left in the 3rd period, Philadelphia was dinged for not one but two minor penalties at the same time. And on the ensuing 5-on-3 power play, Scott Hartnell banged in a loose puck to tie the game up.

https://www.nhl.com/video/embed/hartnells-late-game-tying-goal/t-290860626/c-53362803?autostart=false

Philly, however, decided there was something not quite right about Hartnell’s goal. They thought that Filip Forsberg may have snuck into the offensive zone just slightly ahead of the puck on the zone entry that preceded the tying marker. The Flyers decided to challenge, hoping that video review would negate the Preds’ goal and put them back on top with just under two minutes to play.

When news first came out of the league’s proposal to change the rules, there was a lot of skepticism that it would act as much of a deterrent to frivolous challenges. While no coach wants to see their team go on the penalty kill after conceding a goal, the odds were still stacked pretty heavily in favour of challenging even in low probability scenarios. In a normal even-strength situation, your probability of success doesn’t need to be all that high in order to make a challenge worthwhile, in fact you’re safe challenging a lot of the time with less than a 25% certainty of success.
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