In sports positive EV can happen a lot based on real world circumstances. Hot streaks are real, injuries and line ups change before and even during games, players get arrested, etc. Often times opening lines move drastically because the books just don’t know the true odds. In practice the books move the line so they make a profit. Example everyone would bet on chiefs over lions by a touchdown all day long; a line might start there but move quickly. It’s quite amazing that final line is almost always 50/50 win probability.