A -3 favorite winning by exactly 3, or a game landing exactly on a total of 44, pushes. The push probability is priced into whole-number lines - it is the entire difference between -3 and -3.5, and in the NFL, where margins cluster on 3 and 7, that half point is worth real money. In parlays, a pushed leg usually reduces the ticket to the remaining legs rather than killing it.
Push math is why the point value on each outcome in a spreads/totals payload matters as much as the price: comparing -3 (-105) against -3.5 (+100) is a push-probability question, not a price question. Historical closing lines from the archive let you measure landing frequencies on key numbers directly.