After creating your events inside the calendar, players can enter reflections upon the conclusion of those events. They can rate themselves and indicate how they played, and also leave a comment to give context to their ratings.
This score goes into the Performance tab on the summary screen (the score is the average of the player and coach ratings combined).
To view the individual or group scores on a particular event, select the Events Tab, navigate to the event (only past events will have a performance section) and tap on the Performance Ratings button.