I don't think it was much of tactical masterpiece TBH, he attacked in the most obvious place of all.Best tactical race move: Bettiol picking the right moment at Flanders
The less obvious move of Langeveld bridging Sagan and Kristoff back to the first group behind Bettiol worked out brilliantly, though. One could think he should not pull a group if a rider from his team is solo leading the race but he brought back a couple of quick guys to the group with him, which then disrupted the chase.
You can see that here at 4:00