Overlays

Where the money actually is

6 minLesson 4 of 8Core

An overlay is a horse the board is paying more than it should. You think it wins 22% of the time (about 3.5-1 fair), but the tote has it at 6-1 (only ~14% implied). That gap — your number minus the market's — is your edge. Bet enough real overlays and the prices pay you back even though plenty of them lose.

Drag the two sliders and watch the needle. You only fire when the edge clears the threshold.

Your fair win %

22% (3.5-1 fair)

Board odds (to-1)

6.0-1 (14% implied)

underlay (market knows more)fairoverlay (you have value)

Edge = your % − market %

+8%

OVERLAY · BET

An overlay is a horse the board prices LONGER than your honest estimate — they're paying you more than the risk deserves. You only fire when your edge clears the threshold. Everything else is a pass, no matter how much you like the horse.

Overlay, fair, underlay

Three outcomes. Overlay (your % > market % by the threshold): bet — they're overpaying. Fair (about equal): pass — no edge, and the takeout eats you. Underlay (market % > yours): hard pass — the crowd knows something you don't, and you'd be the sucker giving them value.

The threshold is your seatbelt

We require the edge to clear ~2% before calling it an overlay, because your estimate is fuzzy. A 0.3% edge is noise. Demanding a real gap keeps you from betting horses you only slightly like — the bets that quietly lose to takeout.

Why most "good horses" are passes

The hardest discipline in this game: loving a horse and not betting it. If the board already has your sharp contender at the right price, there's no overlay — no money in it. Value isn't "is this a good horse?" It's "is this horse mispriced?" The Scanner exists to surface exactly those mispricings so you don't have to eyeball every race.

Takeaway

Bet the gap, not the horse. Overlay = your fair % beats the board by enough to matter. Everything else — however much you like it — is a pass.