What four contest matches are on the Contest Upsets Mount Rushmore?

Board 8

Kinglicious posted...
Frog was slightly favored on B8 but a huge bracket buster. But I'd consider any bracket buster an upset, regardless of our opinions.

I mean I feel like the spirit of the question is what was surprising to us.

If you want a Chief match that he was actually favored to win on B8 and was a huge bracket buster, the pick is Sub-Zero > Chief (still the lowest prediction percentage for a round 1 one-on-one match, I believe).
https://imgur.com/WqDcNNq
https://imgur.com/89Z5jrB