Are Overs or Unders Better?

The real return of blindly betting overs vs unders on player props, settled at the closing line across more than 1 million graded props. Unders lose less in every sport, because the public bets overs and books shade the over price.

Blind ROI by sport

Return on betting every over vs every under, 1 unit flat, settled at the closing line. The gap between the bars is the over/under bias.

Bets

661,955

Over win %

42.5%

Under win %

57.4%

Avg over odds

+185

Avg under odds

-131

MLB over time

Cumulative blind ROI; where it settles is the long-run edge. Gray bars are bets settled each month.

Props included

What went into MLB and how each prop settled, on the closing line. Win/Loss/Push are the over side (a loss is an under win); void = no action, pending = not yet graded.

Prop	Bets	Win	Loss	Push	Void	Pending	Over ROI	Under ROI
Total Bases	247,778	120,856	126,922	0	38,303	2,323	-8.0%	-6.0%
Hits	120,386	68,147	52,239	0	20,181	1,731	-6.9%	-8.0%
Stolen Bases	61,805	5,074	56,731	0	8,755	4	-45.2%	-1.9%
Runs + RBIs	42,399	20,297	22,102	0	7,704	5	-6.0%	-6.3%
Home Runs	33,305	4,695	28,610	0	4,214	265	-22.7%	-5.2%
Pitcher Strikeouts	22,680	11,278	11,306	96	2,123	890	-5.9%	-7.8%
Singles	18,682	8,399	10,283	0	2,750	0	-11.7%	-9.6%
RBIs	18,648	5,538	13,110	0	2,663	0	-17.6%	-7.0%
Runs	18,590	7,085	11,505	0	2,471	0	-15.9%	-7.4%
Walks Earned	17,352	5,553	11,799	0	1,709	0	-17.0%	-7.6%
Earned Runs Allowed	17,077	8,054	9,023	0	1,753	200	-10.6%	-3.4%
Doubles	14,516	2,325	12,191	0	1,626	0	-28.6%	-4.2%
Pitching Outs	14,331	7,272	7,013	46	1,252	514	-6.1%	-9.0%
Hits Allowed	12,022	5,859	6,136	27	588	178	-8.8%	-6.4%
Pitcher Base On Balls	1,675	865	810	0	42	0	-7.8%	-13.1%
Hitter Strikeouts	479	228	251	0	27	0	-14.4%	-6.4%
Walks Allowed	230	113	117	0	7	0	-14.9%	-9.6%

Over vs under ROI by sport

Blindly betting every over vs every under, 1 unit flat, settled at the closing line across all books. A negative number loses to the vig; the gap between the columns is the over/under bias.

Sport	Graded props	Over ROI	Under ROI
MLB	661,955	-13.1%	-6.2%
NBA	375,339	-8.7%	-3.8%
NHL	158,686	-9.5%	-4.7%
WNBA	39,447	-10.5%	-3.3%
NFL	36,926	-15.8%	+2.1%
CFB	17,790	-10.3%	-1.5%
CBB	8,157	-15.4%	+3.3%

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Drill into the lopsided markets

Sport-level is the headline. The edge is in the detail: which books shade hardest, which prop types are most one-sided, and which players the lines consistently misprice. Subscribers get the full breakdown by book, prop, and player, plus saved reports.

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How this connects to devig

The standard way to remove the vig from a line (the multiplicative method) silently assumes the book split its juice evenly between the two sides. This page is the proof that it doesn't. When overs are shaded, a plain devig hands you a fair line that's still tilted. Our devig calculator factors the measured bias back in.

Frequently asked questions

Are overs or unders better in player props?

Across every sport we track, blindly betting unders has lost less than blindly betting overs, settled at the closing line. The public leans overs, so books shade the over price, which makes overs the worse blind bet. Neither side beats the vig on its own — the point is the gap between them.

How is the ROI calculated?

Every graded prop is settled against its closing line. We assume a flat 1-unit bet on the over (and separately on the under) at the closing decimal price: a win returns price minus 1, a loss returns minus 1, a push returns 0. ROI is total units divided by number of bets.

Does this mean I should bet unders?

Not blindly. Both sides lose to the vig long term. The bias tells you which side books shade, which matters when you devig a line — a plain devig assumes the juice is split evenly, and on props it isn't.