The Cubs-Cardinals rivalry -- the encased meat of baseball feuds -- is always near at hand, you see. Within the bounds of that jersey back you see a reference not only to the Cubs' 105-year World Series drought, but also to L'Affaire Bartman. The troll is strong here. Strong indeed.
Anyhow, the gentleman in question says he makes a new such jersey each year and retires the old one, which he may or may not toast alongside the '72 Dolphins, who are always available for such occasions (to say nothing of Bar Mitzvahs).