We went from a clump at the top to sparse company. There are now only six people under par, clearly less than the U.S. Open. And only one man stands on a lead. This man has no experience with this sort of pressure, as it's his first 54-hole Open Championship lead in his 20 years of Open Championships.
So, what is possible? Well Dustin Johnson is right there, so let your imagination play.
And while it's playing, let's use some of the past comebacks in British Open history to imagine some potential finishes.