What Does a +1.5 Spread Mean? A +1.5 spread is commonly seen in baseball betting, the standard runline  for MLB. This spread means the underdog must win outright or lose by exactly one run to cover the spread. Alternatively, a -1.5 spread means that the favorite must win by at least two runs.

If you take a player +1.5 sets in a best-of-three match, all your player needs to do is win one set. Vice versa, backing somebody at -1.5 sets would mean that they need to win in straight sets. And if it's a best-of-five match, a -1.5 bet would mean that your player can only afford to lose one set.