Should KTRB keep dropping off during games at night enough, or go off entirely, the A's could cancel their agreement with the station. After all, the primary purpose of the deal is to get them coverage for their games in the Bay Area.
The A's were formerly on 960. The present ownership didn't like it because they couldn't hear the night games well past the East Bay hills. The station has to protect the Canadian clear channel station on 960, and has a major null that runs Northeast of Concord.
910 had to give up about 15% of signal towards Contra Costa when it went to 20Kw. So in the Bay Area county with the most conservatives to garner, they have less signal. It doesn't seem likely that they would want to be the so far down in the pecking order of sports stations. It would be very hard to make any money.
It would seem that neither of these stations would be satisfactory to the present A's ownership, and without a baseball team, it's not easy to have a successful sports station.