A logistical model of the Top 11

I’ve been playing around with the numbers, and am able to get a decent projection model with relatively few assumptions. The model is not yet amazingly statistically significant. Nevertheless, the predictions are interesting.

The model assumes that the primary indicators of elimination are Gender, Slot, and whether or not the contestant scored in the bottom 3 on Dialidol and WNTS. You can download the full data set for Top 11 episodes (S4-S9; male is coded as 1, female as 0, and bottom 3 is 1 for yes, 0 for no). Now, we can use R to get a logistical fit Continue reading

Surprise elimination and the save rule

Casey Abrams had the lowest number of votes last night, even though he was a highly popular contestant, with plenty of name recognition, and had previously never been in the bottom 3. He was voted in by the public, not a wild card. How often does it happen that a contestant is eliminated without his fans knowing that he was in trouble?

Excluding the first two rounds of the finals, and the top 3, it has actually happened 15 times.

Season 1 Tamyra Grey was eliminated from the Top 4
Season 2 None
Season 3 Jon Peter Lewis in the Top 8
Season 4 Nikko Smith in the Top 9
Constantine Maroulis Top 6
Season 5 Mandisa from Top 9
Season 6 Chris Sligh Top 10
Gina Glocksen Top 9
Season 7 Chikezie from Top 10
Ramiele Malubay from Top 9
Michael Johns from Top 8
Season 8 Megan Joy Top 8
Season 9 Didi Benami from Top 10
Andrew Garcia from Top 9*
Michael Lynche from Top 9 (saved)
Siobhan Magnus from Top 6

*During a double-elimination week

You can see that nearly all of these eliminations happened in the Top 8-10. I think this is kind of interesting, actually. I’ve heard of the judge’s save referred to as the Chris Daughtry rule, but this is wrong. Daughtry’s fans had every reason to believe he could be in trouble: he was in the bottom 3 during the Top 7 round, and was eliminated in the Top 4. What this should really be known as is The Constantine Maroulis rule! Similarly, the season 8 save was Matt Giraud, but he was in the bottom 3 in the Top 10 round and saved in the Top 7. That’s not very far removed. If his fans really just weren’t voting because they thought he was safe, they sure don’t have a very long memory.

Surprise eliminations like Casey are inevitable in Idol, particularly in the first few rounds, after people have seen their favorites sail through and start voting for their second favorites—ones they like, but aren’t sure are safe. However, these make it damn hard to predict what is going to happen in the first volatile weeks. The judges save has been invoked twice rightly, once wrongly, and in each case for men.

In the future, any predictive model is going to need to take into account dialidol or some other measurement, because the results alone would never have had any indicator that Casey was in danger, let alone the losing competitor. He was male, went first (historically not a position that was dangerous), had lots of pre-exposure, played an instrument, chose interesting songs—last night never should have happened. The fact that it did shows just how strange the voting public is.

Final 11 Post game: one of the craziest results shows ever

Three people in the bottom 3 who had never been there before. It’s only happened twice in 57 before (3% of the time):

Season 4, Final 9, Scott Savol, Nikko Smith, Vonzell Solomon
Season 5, Final 9, Elliott Yamin, Paris Bennett, Mandisa

I’m inclined to say that model could never have predicted that, but the system clearly needs a lot more refinement. Part of the problem is that the ratings were based on a few individuals, instead of a broad base survey. I’ll rerun the numbers when those numbers become available.

Still, just a shocking result. Without having seen the show, I can’t believe it.