Unless you're involved with one of the teams or very rich, there
is no real ethical consideration. Line Gambling is a pari-mutuel
pool (like horse racing) where there are three possible outcomes.
1. Favorite wins and covers (group 1 wins). 2. Favorite wins and
doesn't cover or loses (group 2 wins) 3. Favorite wins by exactly
the line (house wins, group 1 and group 2 lose).