If you think back about four weeks ago, I posted TV Power Ratings, Part One. The purpose of Part One was simple—rate the importance of a program to its network during the week it aired. I call this number the show's Relative Network Rating.
But that's only the first contribution to a show's overall Power Rating. What else do we need to consider?
Think back ten years ago when "The Single Guy" was consistently rated as one of the top ten shows every week. It was highly rated, but was it powerful? Hardly. It was tucked nicely between "Friends" and "Seinfeld," and attracted far fewer households. Plus it was part of Must-See TV. Only the most-watched network night at the time. Put all of this together and what do you find? "The Single Guy" had a relatively low overall Power Rating. A low Power Rating indicates that the show won't attract much of an audience if it moves out of a cushy timeslot into a less desirable timeslot. (This notion was confirmed in late March 1997 when "The Single Guy" moved to Wednesdays at 8:30PM. The show was rated #7 for its last week on Thursdays and #62 for its first week on Wednesdays.)
After thinking about this example, the second contribution is quite clear—compare each program to the lead-in and lead-out programs. That's really not a revelation. TV experts like Marc Berman frequently compare ratings of a program to the ratings of preceding and succeeding shows.
I'm going to make this comparison even simpler by comparing every show to the highest-rated show of the evening on the same network. I define a show's Hold Rating as
Hold Rating = ([Show Rating]/[High Rating] - 1)*5.
The [High Rating] is, of course, the rating for the highest-rated show on the same network and the same night. I subtract "1" so that the quantity is always a negative number—the Hold Rating should penalize shows for not being able to hold an audience. I multiply the difference by "5" so that the range of the Hold Rating is similar to the range of the Relative Network Rating.
I then compute the Power Rating by adding the two quantities together,
Power Rating = Relative Network Rating + Hold Rating,for every airing.
Finally, I calculate the Total Power Rating by taking the average value of all airings,
Total Power Rating = Average(Power Rating).
If a show has a high Total Power Rating, that series is quite valuable to its network. Likewise, if a series has a low Total Power Rating, a network is very likely to cancel (or not renew) that series.
You can look in the near right column for this new feature. This week I present the series with the top 10 and bottom 10 Total Power Ratings in 2004-2005. I'll add Total Power Ratings for other years, including the current year in the coming weeks.