Perhaps they should try and track how many concussions, diagnosed and undiagnosed, each had.
“... track how many concussions, diagnosed and undiagnosed, each had”
I think that could be an issue. Some people who suffer from concussions have mood swings and bouts of depression (all neurological). I wonder if they got depressed and already had painkillers as a result of such damage to the body due to hockey.