make it possible to copy things
Being able to copy games, leagues, calendars, etc would be helpful. Many times the information is the same from one to another except maybe a few minor changes. For example, if I know two teams are playing multiple times in a season but only the date and time would change it would be quicker to copy the event and then modify the date and time.
Matt Haffner commented
Check out the Duplicate Post plug-in: https://wordpress.org/plugins/duplicate-post/ . It will add a copy button to all your post types.