BLAKbets

Middle betting calculator

Back over a lower line and under a higher line at another sportsbook. Enter both lines, prices and bankroll to see stakes and possible returns. Read the walkthrough on Middle .

lower line

higher line

Window: 22, 23. Break-even threshold: the result must land in the window more often than 2,56% of the time.
Over stake
$50.00
Under stake
$50.00
Outside window
−$2.50
one leg wins
Inside window
+$95.00
both legs win

Pure maths. No sign-in needed. Amounts are in USD, just like the platform.

Let the scanner find your next opportunity

The BLAKbets middles board shows both results for each pair: inside and outside the window, with calculated stakes and an odds freshness indicator.

View plans

No trial period. See plans and prices on the homepage. Adults aged 18+ only.

Formula

How we calculate a middle

  1. 01

    Stakes calculated like an arb

    Leg stake = bankroll × (1/odds) / sum(1/odds). Equal payouts give the same outside-window return.
  2. 02

    Two outcomes

    Outside: one payout − bankroll. Inside: both payouts − bankroll.
  3. 03

    Break-even hit rate

    Threshold = loss outside the window / (result inside the window minus result outside it). This is how often the result must land inside the window to break even.

Example

Example: tennis, 21.5 and 23.5 games at odds of 1.95

Questions

Frequently asked questions

What is a middle window?

The results between two lines that win both bets. Over 21.5 and under 23.5 games have a window of 22 and 23 games.

What is the break-even hit rate?

How often the result must land inside the window for double wins to cover outside losses. This is calculated from your prices, not a prediction of match outcomes.

What happens on a whole-number line?

A result exactly on a whole line refunds that leg. The calculator shows that scenario separately.

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