Shot Based Metrics and AHL Systems
Technology has blown open the doors of possibility providing opportunities for fans, writers, journalists, scouts and hockey professionals to expand the fields of analysis, with the end benefit being greater insight.
The current spotlight is shining a light on possession metrics at the NHL level, with broadcasts even showing expanded stats with the Buffalo Sabres providing intermission breakdowns.
Like this example:
I guess if any local broadcast would talk Corsi, it’d be Buffalo’s but this still surprised me. Good job, MSG. pic.twitter.com/Yl6sGkZepO
— Fear The Fin (@fearthefin) November 7, 2013
Josh expanded on this:
One of the main proxies for possession is Fenwick – the summation of shot attempts for both teams at even strength (less blocked shot), either represented as a differential or a percentage. Teams over 50% are strong possession teams, while teams under are usually struggling. Nicholas Emptage compared the Fenwick Close % to Shots For % of all NHL teams over the last five years and found an r correlation of 0.925. Over a large sample size Shots For % and Fenwick Close % become quite close.
To create a proxy for possession in the AHL, I looked at all games that have been played so far this year (up to 13 November), added up each teams Shots For and Shots Against and calculated their Shots For %. I executed this with a Python script so during the season I can continue to update these numbers.
The following are the top-5 with the Stars as the headliners.
|San Antonio Rampage||600||516||53.76%|
Results require further refinement and an expansion of data to add value, but with the lineup that includes AHL leading scorer Travis Morin, the concept of the Stars outshooting their opposition by a wide margin is likely, although it’s effect as a factor in winning games has yet to be determined.
As the Texas Stars skated with the Toronto Marlies, I was able to image some of the Stars special teams formations and while the possession metrics were only glossed over, this is primarily a systems piece.
Using a handy little app called Hockey Dood, while the Stars setup the powerplay or started to try to kill off a penalty, I took a snapshot of how players were positioned on the ice.
I’ve been fascinated with systems for a long time, not only learning basic formations, but trying to understand why formations were used and how they are built for success along with the counter to stop a successful system. I’ve failed to explore individual team systems while scouting players in the past, but started slowly incorporating the role of players in the system.
Technology now allows users to document very simple images and I will try to present these in addition to prospect viewings with any associated commentary.
Panning back and taking the focus from isolating player’s tools and development and evaluating where they fit seems to be the logical next step in evaluation. I can’t proclaim a distinct expertise as I’m still learning some of the more advanced methodologies, but I like the idea of applying practical skills into the coach’s template.
Documenting where players are in their skill set is the main goal, but placing them within the confines of coach’s vision provides context. I’m encouraged to find better clues and analysis drawing distinction between skill and utility.
An example of the type of questions that a system’s focus can enhance – or be a detriment.
- Does a player stay within the concept of the system? Does he stray? How often? Is he reprimanded with lessened ice time as a result of straying?
- When the circumstances call for a break in formation, how quickly does the player relative to his teammates return to formation?
- Is the coaching staff developing plays/systems with his players skillsets in mind or forcing players to stick within the confines of his desired system
- Are coach’s utilizing a stifling or free-flowing system and how does that affect individual players/prospects?
- What affects on player’s skills development are there and as an extension, is this conducive to proper prospect development?
Initially I’m going to limit system images and commentary primarily to special teams, unless something very special manifests as a strong example of enhanced benefits. In other words, if there is value to additional system’s commentary or overall strategy I will include it.
The internet is chock full of solid resources found with the simplest Google searches with these three resources that I have found invaluable over the past couple of years as I delve deeper into systems.
The first resource is a timeless reference by former NHLer, Ryan Walter and Mike Johnston. Whether you’re a coach, writer, or a casual observer with an interest in systems, this is a great introductory resource. It’s not necessary to get the proper naming conventions for each individual system, as it is to identify the pattern, and its uses.
The other is Coach Nielsen an invaluable website that documents plays with diagrams, video and great insight.
The third is a great resource compiled by ‘The Suit’ in this reference library that uses very simple methods to explain systems.
Visit either of these sites for an expansion, as my description here doesn’t do the content justice.
TEXAS STARS SPECIAL TEAMS
The Stars utilize a ‘front’ formation essentially when the opposition enters the defensive zone and is attempting to set up their own powerplay formation. As a first blush attempt, the goal is to disrupt and act as a deterrent to the powerplay set up and in return limiting any attempts to the get the puck to the net. The end goal of is to move the puck/play to an isolated area of the ice, allowing the penalty killers to engage the powerplay unit, create a turnover and then clear the zone.
The working concept is the winger lines up ahead of the center or ‘fronts’ and forces the puck holding defenseman to one side of the ice whether by skating it or passing it off. The high penalty killing forward then follows the defenseman or the puck over to the same side of the ice. The center follows suit, with the edge of the slot acting as an invisible border, blocking passing lanes with presence and with an active stick. Defensemen take up positions in front of the net.
If the powerplay ends up setting up successfully and the attempt to create a turnover fails to materialize, the penalty killers set up in a box to defend against the formation. The Toronto Marlies use an overload powerplay setup – with slight variations where the weak side defender at the blueline drops into the slot area or lower – but the box sets up to take away the middle of the ice and allows the two high forwards to collapse to the net if need be, while taking away the top of the zone and potential shots from the point.
This is a good example of how multiple formations can exist at different intervals of the same penalty and how they fit like a puzzle. If there’s a shot attempt and the team on the powerplay breaks formation to regain possession, the penalty killing team has the option to stay in the box, or move back into the fronting formation depending on where the puck retrieval occurs.
There is more to setups than the powerplay team in the offensive zone, with controlled breakouts and regroups playing an important role, along with zone entries and the decision to use a dump in over a controlled entry. This image will only focus on the offensive zone formation.
Most teams puck retrieval is in an overload formation (see Texas Box PK image for an example of the powerplay overload formation), however, once the set up has been established change it up into different patterns.
Lately a general inclusion of a 1-3-1 PP formation across the league has spawned variations and the Stars are no exception however, there’s a variation to that where it’s like a hybrid 1-3-1 and umbrella formation.
They line up with a high point defenseman and two players at the top of the face off circles, usually the second blueliner dropping down to the right circle, controlling the half boards. On the second unit, that point man slotting in on the right of the umbrella is 2nd round pick, Brett Ritchie.
The center will take up position in the slot to provide an option and heads to the net once the puck gets back to the point for the shot and then once again drop back into the slot as a distribution option to get the puck into a scoring position. The movement also attracts a defenseman to the slot and opens up the area at the top of the crease somewhat, adding a lane for cross ice passes.
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