Common tennis spread lines typically include a set spread, where the favorite might be listed at -1.5 sets, meaning they need to win by at least two sets to cover the spread, while the underdog would be at +1.5 sets, allowing them to lose by one set and still cover. Additionally, you might see game spreads, where a favorite could be at -4.5 games, indicating they must win by five games or more, while the underdog would be at +4.5 games, allowing them to lose by four games and still cover.