Mr. Rewrite has already seen his fair share of usage gaffes and agreement errors this football season. This post, from a fantasy sports service, features both.
The first, fare share instead of the correct fair share, comes straight from homophone hell. Here's Paul Brians' take on fair/fare from Common Errors in English Usage. One says farewell when wishing that someone fare well. One pays a fare to get on the bus to go to the fair., where the fare includes a fair amount of deep-fried items. It isn't fair that Mr. Rewrite has to read such poor writing, even if it's free.
As for the agreement problem, the defense (singular) yielded its, not their, fair share of points.