A betting line is a number set by oddsmakers to represent the expected outcome of a particular event. The line is used as a reference point for people placing bets on the event and can be used to calculate the potential payout for a given bet based on the odds and the amount of money wagered.

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. Many baseball games are decided by fewer than two runs.