Last weekends play-offs marked the end of another season, and so I thought it was a good time to review how hockey teams have performed offensively and defensively.
Using data from the past six seasons (this marks the time span of the current league structuring), I have plotted each Premier Division, Conference West, East and North teams goals scored by their goals conceded.
By adding the median to the graph, I am then able to divide teams into one of the four groups marked on the graph. As you can see, teams in the upper left quadrant are the best performing teams, as they are strong offensively (score many) and strong defensively (concede few). In contrast, teams in the lower right quadrant are weak offensively (score few) and weak defensively (concede many).
The graph is interactive. You can include/exclude any league by clicking on their name in the legend. Further, if you hover over a data point you will see which team and from which season the data point represents. Compare teams in the East with teams in the West. If you select East, and then view the graph, it would appear that most teams are to the right of the vertical median, indicating that the majority of East teams are weak defensively. If you do the same for the West, you can see that teams from the West are typically much stronger on defence. This difference in the goals scored between leagues has been further explored below. Owing to the strengths and weaknesses discussed above, we can see that the East Conference has scored the most goals over the past six seasons, the West the fewest. We can also see that for this season, the Premier division scored over 100 more goals than the West. This equates to an extra 0.55 goals per game in the Premier division than the West.
Whilst the terms ‘strong’ and ‘weak’ have been used in this post broadly – indeed there are league winners who have been termed weak defensively based upon the quadrant that they inhabit – it was done to crudely allow me to investigate differences between teams and leagues.