Why does FOX only broadcast one baseball game in each market and block the other.

I'm not sure if this is the right place for this, but FOX has some weird agreement with MLB in which they own the rights to 2 games playing at the same time. I'm assuming it's by region or relevance to the home team, but one game gets broadcast and there's no way I've found (legal or not) to watch the other game. With all of their affiliate stations and the internet as well, why can they not make the other game available? Shit, they own the rights to it. I bet a lot of people would even pay, like us Sox fans in the Southwest.