Using CiviCRM 5.0 I can see an overview of my event participants using the Events Dashboard https://your.domain/civicrm/event?reset=1
Some of the numbers displayed here are however incorrect, in particular the counted/not counted numbers. In my installation all participant roles are configured to be counted. However the Events Dashboard generally reports a significant number of participants as "Not Counted Due to Role". If all my roles are set to be counted, then this number should always be zero.
Am I missing something, or is this a bug (and if memory serves a fairly long running one)?
UPDATE: It seems that the participant count setting in price set fields has a bearing here, based on the comments below (thanks @Aidan for flagging this point). I've never paid attention to the count option in a price set field, a) because I've never really understood what it does (the documentation on this is to say the least, thin) and b) because I've been aware that it has any effect, probably because I've never personally made use of the Events Dashboard page.
So it seems to be the case that when using a price set, if you want the Events Dashboard to count your participants accurately, you should take care to set up your price set so that the count options are correctly configured for your price set. As far as I'm aware, if your price set is not correctly configured, it can mess up not only the numbers on your Events Dashboard, but also the count used to determine whether your event is fully booked or not. As far as I can see the docs and the dashboard only refer to participant status and participant role as determinants as to whether a given participant is counted or not, but it looks like the price set config overrides both status and role.