Moneyline betting is the simplest sports betting format: pick the winner. The odds reflect the probability of each outcome, with favorites offered at negative American odds (e.g., -200) and underdogs at positive odds (e.g., +170).
Moneyline math: A -200 favorite requires a $200 bet to win $100. A +170 underdog pays $170 on a $100 bet. At -200, the implied probability is 66.7%. At +170, it's 37%.
Moneyline vs. spread: Spreads level the playing field by adjusting for margin; moneylines demand you correctly assess straight win probability. For heavy favorites, moneylines require more precision — a -400 favorite priced at 80% implied probability needs to actually win at an 80%+ rate to be break-even.
Finding moneyline value requires a well-calibrated win probability model. Parlaying moneylines amplifies both the expected value (if each leg is +EV) and the vig drag (if any leg is -EV). Most parlay legs are -EV because single-game moneylines already carry vig.
Moneyline line shopping matters most for underdogs. An underdog priced at +140 at one book vs. +155 at another is a 10%+ improvement in payout — significant enough to be worth comparing.