There was a March Madness bracket contest where if anybody got every game right they would win a billion dollars. Some guy got the first 32 right.
If I did one today I'd just pick the I wanted to win and go with it- unless there were some glaring ones- though there never really are, in reality. You lost me here.
There are several games where I don't know much about both teams or one of the teams. Rather than flipping a coin, I went with the betting favorite.