As noted here I signed up for basic cable this year but have not been watching it much. One reason is most of the Met's and Yankee's games are on premium cable. However today's Met's game was on Fox so I watched part of it. I had started listening to the game on the radio before I thought to check whether it was on TV. When I turned on the TV I noticed the radio was about 6 seconds ahead of the TV broadcast so the radio would describe every play before it happened on TV. This is kind of annoying if you would rather listen to the radio announcers. Apparently this is common enough that there is a product which will delay the radio broadcast to match.
There seem to be two theories for why the delay exists. One theory is that the TV signal is delayed so "indecency" can be bleeped lest the network be fined by the FCC. The other theory is the reason is technical, the digital TV signal gets compressed and decompressed, routed through satellites etc. delaying it relative to the radio broadcast. The game was on two cable channels one analog, one digital but I didn't think to check if the delay was the same.