How can the 20 most upvoted opinions be the 20 most controversial? If the opinions were upvoted based on "I agree" (and this is what I assume), then they would

How can the 20 most upvoted opinions be the 20 most controversial? If the opinions were upvoted based on "I agree" (and this is what I assume), then they would be among the least controversial to the stackexchange crowd. Maybe the middle opinions would be better.