Season 3 was the shortest season in Supernatural. There was supposed to be 22 episodes for Season 3 but due to the writers strike at the time, it was cut down to 16 episodes. This the only season to get affected by the writers strike. The rest of the seasons of Supernatural have at least 21 or 22 episodes.
The writers strike pretty much just means that they wanted more money and as a result a bunch of shows that were airing at the time either had to be axed or reduce their episodes in their respective season. So, Supernatural Season 3 which was airing at the time had to reduce the episodes. I never thought I would say this but.. The strike kinda sounds like what we have now. Well, depending on what they wanted.
But it would of been pretty cool to see what it would of been like for Season 3 to have the 22 episodes. But that probably won’t happen. I guess we can dream it. Or think it.