Why isn't this film in IMDB's top 250?
It's been given an average score of 8.1 and should appear in the top 250 but why isn't it? Does anyone know why?
shareIt's been given an average score of 8.1 and should appear in the top 250 but why isn't it? Does anyone know why?
From the bottom of the page with the top 250 list:
The formula for calculating the Top Rated 250 Titles gives a true Bayesian estimate:First there's the possibility of a difference between the ratings of all voters and those of regular voters. Only the latter count for the top 250, but in all probability there isn't much difference between the two groups.
weighted rating (WR) = (v ÷ (v+m)) × R + (m ÷ (v+m)) × C
where:
* R = average for the movie (mean) = (Rating)
* v = number of votes for the movie = (votes)
* m = minimum votes required to be listed in the Top 250 (currently 3000)
* C = the mean vote across the whole report (currently 6.9)
for the Top 250, only votes from regular voters are considered.
The key is that "true Bayesian estimate." Essentially the score on the top 250 list is an average of all of the ratings of regular voters, with an additional 3000 votes thrown in at a rating of 6.9. This pulls down the rating of any movie rated by regular voters as greater than 6.9, and the effect is more pronounced for movies with fewer voters. Check out the ratings of the last ten in the 250:
Position/Title/Bayesian estimate/user rating/number of votes
241. Toy Story 2 (1999) 7.9, 8.0, 101,341
242. Casino Royale (2006) 7.9, 8.0, 159,803
243. His Girl Friday (1940) 7.9, 8.1, 18,921
244. Anatomy of a Murder (1959) 7.9, 8.2, 14,659
245. Arsenic and Old Lace (1944) 7.9, 8.1, 27,341
246. Blood Diamond (2006) 7.9, 8.0, 102,364
247. The Day the Earth Stood Still (1951) 7.9, 8.0, 31,994
248. Mou gaan dou (2002) 7.9, 8.1, 31,811
249. Frankenstein (1931) 7.9, 8.1, 21,608
250. Tonari no Totoro (1988) 7.9, 8.1, 25,220
Note that Anatomy of a Murder, with a user rating of 8.2, places below Toy Story 2 and Casino Royale, which have ratings of 8.0. This is because Anatomy of a Murder has many fewer votes than the other two, so the addition of 3000 votes at 6.9 drags its Bayesian estimate down more. ITMFL, with 22,819 votes, is in the same neighborhood as Frankenstein and Tonari no Totoro, not far away from being in the top 250.
-- TopFrog share