Prop betting seeks to proposition the bettor with a question, one that may or may not have a direct bearing on the final score. For example: How many receiving yards will Tyreek Hill have?
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.