I've heard that historically all the major search engines have used a lot of hand-tuned results (ordering, exclusions) across the highest frequency searches. II

I've heard that historically all the major search engines have used a lot of hand-tuned results (ordering, exclusions) across the highest frequency searches. IIRC Microsoft bought Powerset in '08 just before the launch of Bing specifically to shore up their human tuning. That said, I expected humans to play less of a role by 2020.