Reason for optimism: It's liberating to finally let go of a once-joyous relationship that's been toxic for years.
Reason for pessimism: Immediately after a breakup, it's natural to lament, "I'll never find anyone like them again."
Depending on positive regression for improvement can be a dangerous thing, because regression to the mean shouldn't be the baseline for improvement -- it's regression to your mean. However, it is safe to assume that when a unit posts historically bad results in one year, it could still be bottom-quartile bad the next year and manage to achieve a huge year-over-year improvement. In the case of the Phillies, history tells us a collection of professional baseball players can't possibly have a baseline skill of fielding batted balls that's as bad as the Phillies exhibited last year.