1) Think about the network broadcasting it, and what state they are in pertaining to a scripted average.
2) Think about the duration of the program. Since comedies are oftentimes a half hour while dramas are a full hour, the two are typically compared to other comedies and other dramas respectively.
3) Think about the time slot the show is airing. If the show is airing at 8pm or another time but growing from its lead-in, it is typically more likely to be renewed than a show which airs behind a massive hit (The Big Bang Theory, Modern Family, Scandal, etc.) and loses much of its lead-in.
4) Think about the competition a show has. If it has to go up against NCIS and The Voice and gets an average rating, it may be a more likely renewal than a show with a similar rating going up against shows with less ratings.
5) Think about the production company. In a scenario that only one could be renewed and they get similar ratings, ABC this season would most likely renew Blackish over Fresh Off The Boat because the former is produced in-house while the latter is produced by 20th Century Fox, so they would have little to no benefits of the show reaching syndication. Also, a show like Marvel’s Agents of SHIELD has a bigger cushion in terms of renewal because of the advertising that is done to Marvel characters and movies, as both ABC and Marvel are owned by Disney.
6) As mentioned earlier, 8pm shows are often cut more slack for the fact that they self-start the night, so the possibility of having viewers watching it that simply left the TV on from the last show is simply reserved to shows outside of primetime such as Jeopardy. Also, 10pm shows are oftentimes held to lower standards due to the fact that many viewers have started to go to bed. The epitome of this is Sunday at 10, as not only in the fall do the shows (Revenge and CSI) go against football, but also have the displeasure of the fact that many viewers go to bed early in attempt to get an extra-good start to the week.