While basketball and football betting lines are based on the scoring differential between two opposing teams, the way betting lines are set up for baseball and hockey are different. Because scoring is so limited in baseball games and hockey matches compared to relatively high-scoring football and basketball games, it would be nearly impossible to come up with truly effective betting lines based on differences in team scoring. Most lines likely would be within a couple runs of the other team in baseball and nearly impossible to place at other than one or two goals in hockey. So instead of using traditional side bets for those two sports, odds-makers have bettors place wagers based on which team will win with the vig adjusted accordingly. Totals bets for scoring essentially are the same for all sports, but the side bets do differ.
https://www.businessinsider.com/sweat-in-the-game-a-gamblers-grind-in-the-nba-2011-4
