I've watched keywords climb from the 60's to the 50's and right when they get on the verge of breaking into the top 40... they drop to the end. Which tells me that without the re-ranking they would be somewhere near the top.
Just had a site do this. It was -950 and had been going up for weeks after deoptimization. It went to -150 almost instantly, then -90, then -60... as it approached -40 it is now back to -950.