Powerful transitional metrics? DZ transition QUALITY for defenders and OZ transition QUANTITY for forwards!

NHL fans around the world are getting more and more familiar with NHL player hockey cards that mix interesting stats. See the following example made by Andy & Rono.

As Andy & Rono are stating on the card in the bottom right corner, making such cards is possible thanks to data provided by multiple sources. When checking cards like the one above and practicing data analysis with different data sets I always asked myself:

Which stat is the most impactful on the game? And which one is complicated to interpret?

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Spatial dependencies and such

This is about „superior aspects“ of the game (ice hockey, ya know?) that I learned to understand through tracking hours and hours (in last seven years) of hockey. These aspects are:

– time resistant
– league resistant
– (leave alone individual ones) sport resistant

Actually nowaydays when all players have such a quality training and development these aspects are even more crucial than in past.

What really matters the most in hockey is TIME AND SPACE MANIPULATION. Actions leading to this type of manipulation should be built on a will to surprise (deke, fake, deceive, try and evaluate, over and over again) and to be proactive (do not be satisfied with reacting to plays only, try to create, be proactive).

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#xGextraliga: Lessons from disassembling xG by types of attack

We know that xG (expected goals) metric is a very precise represenatation of team strengths on the ice. It is time to look at components of the metric. We can approach this in various ways – by location, by shot type, by different score, by dangerous possessions or by types of attack. The last option is enabled by tracking 2020-21 xGextraliga data and I select that for this article.

These are components of total xG tracked (75 games, 432 xG, 437 goals):

  • 5v5 quick attacks = also called „rush attacks“ where the attack is counted just a few seconds after entering the offensive zone, odd man rushes are included here
  • 5v5 slow attacks = team enters the offensive zone, holds onto the puck a attacks from the pressure
  • 5v5 OZ steal attacks = team wins/steals the puck in the offensive zone and attacks from that possession
  • 5v5 OZ face-off attacks = all possessions that started with the offensive zone win, if a team leaves the zone a new possession is counted
  • PP attacks = all power-play offence
  • SH attacks = all shorthanded situations offence
  • EN situation attacks = all offence created with a goalie pulled by one team
  • 3v3 situation attacks = usually an overtime hockey
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#xGextraliga: How much do different metrics matter in hockey?

One of the main reasons for designing my data for xGextraliga project was to identify which metrics matter more than others in the game of hockey. This article selects six main metrics, compares them to each other by calculating correlations to winning (more accurately to goal differentials from games). These include:

– unblocked shot attempts (also known as „fenwick“)
– score-adjusted unblocked shot attempts
– screened unblocked shot attempts (only offensive player screen considered)
– expected goals (based on past researches in the NHL, this will be discussed in a separate article)
– clear path opportunities (= shooter is positioned in the slot area with no block close to him)
– odd man rush opportunities (= 3 on 2, 3 on 1, 2 on 1, 2 on 0, 1 on 0 rushes)

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#xGextraliga data: Score effects and more

You probably know it yourself. The game ends and following stats are shown to you:

Goals scored: 1:3
Shots on goal: 29:21

TV reporters might comment on how the home team deserved a better fate due outshooting its opponent.

What if the away team scored early and led throughout the game? Would it impact „shots on goal“ stats and its quality? Oh yes, it would. This article attempts to explain what usually happens when one team gets to the lead. It uses data from Czech top men league (Extraliga) and compares them to findings from the NHL. Sounds aight? Let´s go then.

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Did anything break for Russia? #WorldJuniors# FocusOnRussia

Russian junior hockey team had a surprising appearance followed by surprising dominance at November´s international Karjala Cup, the men tournament showcasing Russia, Finland, Sweden and Czechia. The young team won it and I summarized how did they do it in the article. Lot of optimism led to disappointing finish for Russia at the World Juniors after losing bronze medal game to Finland. Combining my eyes and unique data I tracked I found three points that could be behind the slow but steady fall.

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