What we are calling “Team Possession” is a proxy measure taken from shots-for and against in the first two periods and expressing them as a percentage (2 shots-for + 2 shots-against = 50%), called 2-Period Shot Percentage or 2pS%. This measure has been tested and shown to be very close to our modern possession measures.
The data is split 1952-53 to 1992-93 and 1993-94 to 2014-15 for reasons explained in the introduction for historical team comparisons.
The charts below include both cumulative and 20-game moving averages of the measures, as well as +/- 1 standard deviations from league average (50%) for the seasons queried. Personally, for any one season I prefer to show +/- 1 standard deviation in the measure and then the team’s measure in-question, but it’s up to you. To choose different seasons and lines, click on the grey “Report” bar, then select “Filter.”
If you’re stumped as to which seasons you should query, you might find our franchise possession and shooting history charts helpful; they depict each franchise’s entire history, and can indicate some of the seasons where drastic changes took place.
P.S. Some of the limits of the display are really just the limits of the embed and WordPress. If you have an Office Online account, you can click on the bottom right icon below any of the graphs to see the data; if you don’t, you can still download the document by clicking the left-most of the icons in the bottom right.
If you need help with learning how to use the graphs, or troubleshooting, or have questions, suggestions, or data requests, please check out our tutorial.