WAR On Ice: The Blog

Editor’s Note: This post was written by Emmanuel Perry (@MannyElk) and Ryan Stimson (@RK_Stimp) to describe their crowdsourced projects. We are happy to partner with them to help join their data back to our database, not just to spare them to extra work of linking back to the standard set, but to make it easy on them so that it can all be shared publicly.

EP: While listening to a particularly riveting episode of TSN Hockey Analytics featuring one co-webmaster of the site you’re currently reading this on, I heard something that piqued my interest. Andrew Thomas stated his openness to hosting fan-sourced data on the site and went on to mention he had begun working with Ryan Stimson to try and make this happen. I was already aware of Stimson’s Passing Project and was excited at the prospect of having such unique and valuable information shared publicly on an established online platform. I myself had been involved with collecting and sharing manually-tracked data of a different type, but had not considered expanding this project until now.

I believe fan-sourced data will provide the tools we need to advance this field into a new era. Certainly, in the absence of chip-tracking technology, this new data can catalyze new ideas and take our analysis of the sport new places. Good things don’t always come easy and indeed, entire seasons worth of data require thousands of often tedious hours. Projects like Stimson’s and mine require a collective effort and I’m asking for your help. Before I go on, here’s a little bit on our respective projects:

RS: The Passing Project

As the hockey analytics community gathers more information on how goals are scored, there’s been an emphasis on pre-shot movement and passing. Steve Valiquette introduced the concept of the Royal Road. The link Manny provided in the opening paragraph discusses the fact that teams shoot at a higher percentage as the number of passes preceding the shot attempt increase. The focus of this project is on capturing what happens prior to the shot attempt in several forms: sequence (one pass, two passes?), location (offensive zone passes, transition passes, Royal Road passes?), and efficiency (which players generate shots more often than others?). As we’ve gathered data on 340 games from this season alone, I’m more confident than ever in saying that what happens before the shot is attempted matters significantly more than where the shot is taken.

If you’re curious how we do this, you can visit this page where myself and five of my trackers take you through a period and explain what we do. For more detail, you can read some of my earlier findings from the hockey analytics conference at Carnegie Mellon University here and watch my presentation here (I start around the 20:00 mark.)

EP: Between The Lines

Our goal is to collaboratively record all blue line events during the 2015-2016 NHL season. In addition to zone entries, all instances of the puck entering or exiting a zone will be recorded. Thus, the location of the puck is known at any given second, allowing us to extrapolate stats dealing with zone time or transitions. In particular, these stats bring us closer to identifying specific aspects of the game on which players can have a direct positive or negative impact. I outlined potential applications of this data in my presentation at the hockey analytics conference at Carleton University in Ottawa, which you can listen to here.

Since Ryan’s project was initially proposed, he’s received significant interest and has accrued a handful of volunteers. In the few weeks since I proposed mine, I’ve gotten similar interest for which I am very grateful. In order for these missions to come to completion, however, I regret to say we’ll need more help. If you’re interested in contributing towards what we both firmly believe is a hugely important movement in the field of hockey analytics, please contact* either of us and we’ll be happy to provide additional details.

EP&RS: In addition to recruiting volunteers, Ryan and I have opened a crowd-funding campaign that you can view here. The money we raise will be put towards GameCenter Live subscriptions for our trackers and compensating Andrew and Sam for the time and effort they will dedicate to processing and hosting this data. [Ed: We'll use it to pay for the server costs. -AT] Know that your donations will go a long way in helping this latent information travel from the ice surface to your computer screen.

Contact information: Emmanuel Perry (@MannyElk) and Ryan Stimson (@RK_Stimp)

Teammate and competition statistics have value for two main reasons:

• Adjusting observed outcomes to account for boosts or drags in performance by factors beyond the player’s control, and
• Assessing the coaching staff’s deployment (“usage”) of a player.

The main two of these are based on all shot attempts (Corsi) and the amount of time these players spend on the ice (since, oddly enough, better players are used more.) Both of these are useful for their purpose, but both are better served by having a summary quantity of these that are predictive of future behaviour, since they reflect both a locally accurate version of player ability and the state of the coaching staff’s current information.

To benefit both these factors (and to make our data processing operation smoother), we first predicted the next game’s CF60, CA60 and TOI60 for each player based on a lag of 30 previous games, then found that an exponential decay model was a satisfactory single predictor of this. For example, we use the formula

TOI60(new predicted) = 0.14 * TOI60 (this game observed) + 0.86 * TOI60 (this game predicted)

to update the game prediction for TOI60.

UPDATE, 2-25-15: We needed a longer “memory” for CF60 and CA60 events, so these are each

Cx60(new predicted) = 0.04 * Cx60 (this game observed) + 0.96 * Cx60 (this game predicted)

To calculate the teammate and competition statistics for that game, we then take the average of each player’s teammates (and opponents) weighed by the amount of common ice time, as before.

In addition, we’ll be adding the exponentially weighted statistics to our player, team and goaltender history once we establish the best predictive measure for each.

So they asked us what we thought:

• John Matisz in the Toronto Sun
• Alison Lukan at Fox Sports Ohio
• Jimmy Hascup at USA Today
• UPDATE, Friday Feb 20: shane Dingman at The Globe and Mail

We had fun talking with all of them, but we’re just as curious as you all are about the new interface coming out tomorrow.

Thanks to Dan Kingerski from 93.7 The Fan for promoting the site and having Sam on the show.

Listen to Sam’s interview here.

We’ve been busy on the development end here at war-on-ice.com, and that’s led to a number of new initiatives, but more importantly, new partnerships. So we’re pleased to announce three primary partnerships, in alphabetical order:

• Mike Colligan (@MikeColligan) is our primary source for information on questions about the CBA and the salary cap. We’ll be cross-posting his FAQ questions to the WARblog and a master list. The first three are here:
  • How do buried contracts work? [http://www.colliganhockey.com/nhl-cba-how-do-buried-contracts-work/]
  • What has the salary cap/floor been in prior years? [http://www.colliganhockey.com/nhl-cba-salary-cap/]
  • What is the minimum NHL salary? [http://www.colliganhockey.com/nhl-cba-minimum-nhl-salary/]
• Alexandra Mandrycky (@alexgoogs) has been utterly indispensable in the assembly of the war-on-ice.com player contracts database, and has also been developing upgrades to our charts, which will not only make them more usable and more pleasant, but will also speed up loading time and allow for additional portability. We can’t say enough good things about her contributions to the site so far.
• Ryan Stimson (@RK_Stimp) is fronting a group of manual trackers as the leader of the Passing Project, who are collecting information on “pass assists” and other pre-shot information. Included in this is the tracking of passes across the line Steve Valiquette has coined the Royal Road, which we will of course think of instead as the Highway to the Danger Zone.

Thanks to these folks for everything they’re doing and will continue to do with us. Give them a follow and help them out if they ask, because they’re making our lives considerably easier and the site all the better for it.