Track condition evolves.
Looks like track condition changes and Verstappen being clever with slipstream did the job for him
Looked like Carlos.
This track is strange. 2016 pole was 29.5 and 2017 wasnt a whole lot faster, but was much faster on other tracks. Basically corners are over too quickly to make up time in high speed. Cars lose time in slow speed and on straights with their boat like behaviour.
As James Allison put it, you give the old regulation cars more love, they went much more quicker