One of the things I have wanted to do for the past few seasons is to record the professions of each player in my matches along with the information (damage, healing, % game, % team, etc) displayed post-match. The introduction of specialisation icons to the PvP scoreboard seemed like a good opportunity to start and also enabled more accurate information to be collected on what classes/builds are the most prominent. The numbers have been summarized below and there are also some basic graphs available at https://imgur.com/a/hvBRLnu.
The total number of matches I'd played this season is 166. Unfortunately, I only remembered to start recording the information after I had played the 10 placements and one extra match, so the following data is for the 155 matches from number 11 to 166. All of the matches were played on a power shatter mirage (Sw/T - GS, Domination/Dueling/Mirage, Demo Amulet) on NA servers. The time I was queuing was generally between 8pm - 12pm AEST (UTC +11).
(Please note that this list is not counting the specialisation i was queuing on, nor does it differentiate between teams. If a player swapped in the pre-match i would record what they had swapped to. Think - "Across 155 games, excluding myself, there are 1,395 players, what were their specialisations?")
It would be cool to see other people collect similar information for Season 15 to see how it compares. If anyone is interested in seeing the spreadsheet let me know and I can post a link.