Is the 'spillover effect' even a real thing? Because I looked through the top openers and I'm not seeing any movies that look like what you'd expect from the spillover effect. Almost every movie that had a soft Monday drop ended up with good legs.
There are a few movies that almost fit the criteria. Civil War and BvS both had soft Monday drops after very harsh Sunday drops, so those don't quite fit. DH2 also had a good Sunday drop, but it was in Summer, after a very frontloaded weekend, so spillover doesn't make sense as an explanation either.
So are there movies that demonstrate spillover?