Is this chart rotten?

Some students pointed me to a FiveThirtyEight article about Rotten Tomatoes scores that contain the following chart: (link to original)

This is a chart that makes my head spin. Too much is going on, and all the variables in the plot are tangled with each other. Even after looking at it for a while, I still don't understand how the author looked at the above and drew this conclusion:

"Movies that end up in the top tier miss a step ahead of their release, mediocre movies stumble, and the bottom tiers fall down an elevator shaft."

(Here is the article. It's a great concept but a bit disappointing analysis coming from Nate Silver's site. I have written features for them before so I know they ask good questions. Maybe they should apply the same level of rigor in editing feature writers to editing staff writers.)

Comments

[5up Mushroom]

Looks more like:

1. Movies, regardless of their final score, are generally scored higher before release
2. Movies that have a higher final score tend to have their pre-release score drop less (duh).
3. Probably some regression to the mean happening here besides the interesting psychology/social implications of high pre-release scoring.

The conclusion that the author drew is sound but it's boring given the rest of the article's premise; that all movies are rated higher before release. Of course crappy movies are going to drop more... zzzzz.