Trading at the open

This is a very old but great tread!

But does anyone have an updated number on this?

How often will the next day close go below or even better than the low of yesterday? (To get filled on close in 88% seem high)

Has there ever been made some kind of calculator that can help us test how the number would be in our own simulation, not just the overall market?

(I found this Slippage research)