Official statistics count many individual players' indicators to assess the quality of their playstyle. The effective actions of the players are recorded and available for viewing by everyone. First of all, this data can be used to compare the players. Sometimes several absolute indicators are required for objective conclusions. For example,points can differ many times for two players, but it is important to pay attention to the games count. And the decisive indicator will be an average number of points (goals, passes) per match. Similar values are available for players grouped by season, so you can see changes in their careers.
When calculating, I take into account all the player's matches and events with his participation. For example, Ryan Dzingel played 71 matches in 2019-20 He scored 6 goals in 6 matches, and scored twice against the Florida Panthers on 8 October. Thus, with 8 goals in 71 games, the average will be 0.11 goals per game. For clarity, the average values are presented for all players, as well as for their roles - defender, goalkeeper or forwards. Ryan played as Cental Forward, only for them this value will be 0.19, and for all Forwards 0.22 Average values are calculated in the same way as the ratio of the number of events to the total number of players participating in matches, taking into account their roles.
Some events are calculated strictly on both sides. For example Hit - Hitter and Hittee are fixed. In the case of averages, the values are the same for all players, but different for roles, for example, for forwards and defensemen. Other events can have an arbitrary number of participants. For example Goal (many assists). Some events have only one participant. For example Takeaway and Giveaway.
In addition, events involving multiple players have a percentage breakdown by opponents' roles. For example, for Blocked Shot, it can be argued that Sebastian Aho blocked attacks from attackers more often than other players. The average across all players and roles provides insight into how others act in the same situations.
All these indicators can be studied on the players pages, the data is updated with the advent of new games. In the future, I'm going to add similar indicators for teams. Suggestions and comments on these calculations can be sent to email@example.com