It takes one franchise going off script to change the entire outlook of an NFL draft.
Look at 2014. Most didn't expect running back Todd Gurley to come off the board as high as No. 10. He did, though, and just like that, there was a slight rush, with Melvin Gordon coming off the board five picks later.
While a mild example, one can see how a draft has ebbs and flows based on players making surprise appearances. This is especially important at critical positions such as quarterback, where one guy coming off the board forces several teams to rearrange their entire approaches.