Both have profitable patterns; neither is universally better. Underdogs have higher CLV potential; favorites win more often. Here's how to think about it and where the math actually lives.
Quick Answer
Neither is universally profitable. +EV is +EV regardless of side. But certain patterns favor each.
Why Underdogs Often Have Edge
Public bias. Casual bettors favor name brands (Yankees, Dodgers, Astros). Books shade underdog lines slightly more attractive to absorb the public.
Plus-money math. +180 underdogs that hit ~38% of the time are +EV. Sharps will fade public favorites and take live underdog opportunities.
Variance. Underdogs lose more often, but when they win, they pay 1.5-3× the stake. Long-run growth is similar; variance is higher.
Why Favorites Sometimes Have Edge
Heavy public bets push underdog lines. When 75%+ of public money is on the dog, the favorite's line shifts to attract sharp money.
Run line favorites. A -150 ML favorite wins by 2+ runs less than half the time (45% of 309 favorites priced -140 to -159 in Bookie Bullies' 2026 game data), so -1.5 needs a price of about +120 or better just to break even at that rate.
Bullpen-decided games. Strong-bullpen favorites at home have higher win-by-1+ rates.
Where the Real Edge Lives
Line-shopping. +180 vs +200 on the same dog is a big EV gap: at a 36% true win probability, +180 is about +0.8% EV and +200 is about +8% EV. Always shop multiple books.
Specific matchup mispricings. Pitcher-vs-team H2H and lineup splits vs handedness are inputs to the Bookie Bullies moneyline model. Weather is not; among published markets it only feeds the first-inning read.
F5 markets. First 5 Innings markets have less public attention; books leave softer prices longer.
The Real Question
Don't ask "favorites or underdogs?" Ask "which side has positive EV at this price?" Some days favor dogs; some days favor favorites. Bet whichever the model + market gap favors.