How to configure the calendar not to sync a specific Google calendar?
This is odd. I'd presume that your Sports calendar events somehow got to one of your other calendars without you knowing. What I'd do is:


first tap on "Hide all" when in Calendars
Next ensure that you do not see Any of your "Sports" calendar events (any events at all from other calendars shouldn't be visible either)
Next start selecting to show the rest of your calendars one by one without ever selecting the "Sports" calendar
The first time you see the culprit events appear - this is the malignant calendar which contains events from "Sports"