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

935,795

Over win %

43.1%

Under win %

56.9%

Avg over odds

+178

Avg under odds

-127

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	351,144	167,746	183,398	0	51,410	1,241	-8.6%	-5.7%
Hits	204,452	115,690	88,762	0	32,065	817	-6.8%	-7.7%
Stolen Bases	87,031	7,494	79,537	0	11,127	4	-42.5%	-2.1%
Home Runs	47,856	6,933	40,923	0	5,254	373	-22.9%	-4.6%
Runs + RBIs	42,399	20,297	22,102	0	7,704	5	-6.0%	-6.3%
Pitcher Strikeouts	37,591	18,268	19,005	318	2,556	872	-7.5%	-6.0%
Earned Runs Allowed	26,890	12,457	14,433	0	2,015	76	-12.2%	-1.9%
Pitching Outs	25,318	13,097	12,171	50	1,432	502	-4.5%	-10.5%
Hits Allowed	22,942	10,965	11,905	72	856	65	-10.4%	-4.0%
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	2,915	0	-15.9%	-7.4%
Walks Earned	17,352	5,553	11,799	0	1,709	0	-17.0%	-7.6%
Doubles	14,516	2,325	12,191	0	1,626	0	-28.6%	-4.2%
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	935,795	-12.8%	-5.9%
NBA	375,339	-8.7%	-3.8%
NHL	158,686	-9.5%	-4.7%
WNBA	100,971	-8.0%	-5.8%
NFL	43,194	-10.5%	-1.5%
CFB	23,162	-11.7%	-0.7%
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.