Masaniello Calculator

Masaniello is a staking plan from Italy for a fixed series of bets. You decide up front how many bets the series has (N) and how many of them must win (K). Each stake is then sized so that the series finishes at one fixed target the moment the K-th win lands — whatever order the wins and losses come in — and stops.

1. Enter the bankroll for the series — the money you commit to it, and the most you can lose.
2. Enter the events in the series (1 to 50) and the wins needed. 10 bets with 6 wins means the plan survives 4 losses; the 5th loss ends it.
3. Enter the odds: one price for every bet, or switch to Odds per event and type each bet's price. American, decimal and fractional odds all work — pick your format once with the Odds format switch.
4. Optionally enter your win chance per event. The calculator then shows how often the plan would reach its target at that chance and what the series is worth on average.
5. Place the first stake. When the bet settles, press Won or Lost: the next stake appears, and the series table keeps track of the bankroll. Undo last takes back a mis-click.

The stake plan lists every stake the series can ask for: one row per bet, one column per number of losses so far. Find the row of your next bet and the column of your losses — that cell is your stake. A dash means the series has already ended on that path.

The plan is worked out backwards from the end of the series. Call V(i, w) the share of the final target you must hold after i bets with w wins:

• Target reached: V(i, K) = 1 — stop betting.
• Target out of reach: V(i, w) = 0 when the wins still needed exceed the bets left — the bankroll is gone.
• Otherwise: V(i, w) = [V(i+1, w+1) + (q − 1) × V(i+1, w)] ÷ q, where q is the decimal price of the next bet.
• Stake = target × (V(i, w) − V(i+1, w)) — a win then lifts the bankroll to V(i+1, w+1), a loss drops it to V(i+1, w).
• Target = bankroll ÷ V(0, 0).

With one price for every bet, V(0, 0) is simply the binomial chance of at least K wins in N bets when each bet wins with probability 1/q — the probability the odds themselves imply. So target = bankroll ÷ P(at least K wins), and the multiplier is one over the chance the bookmaker's prices give your series. That is the whole trick, and it is also the reason Masaniello cannot beat the bookmaker.

Why Masaniello creates no edge

Masaniello only decides how much rides on each bet. It cannot change the odds or your chance of winning, so the series inherits the value of the bets in it. At fair odds the plan reaches the target exactly as often as needed to break even: target × chance − bankroll = 0. A real bookmaker's price carries a margin, so your true chance is below 1/q, and the expected result of the series turns negative — just like every single bet in it. What the plan does change is the shape of the results: frequent moderate wins, and occasionally the loss of the entire bankroll.

That makes it a cousin of the martingale, which also raises stakes after losses and also ends in a total loss when the losses run long. The Kelly criterion answers a different question — how much to stake when you do have an edge — and stakes nothing when you do not. If you are not sure your picks beat the price, check one with the EV calculator first.

Example 1 — 30 bets, 16 wins at 1.85, $100 bankroll

A classic Italian setup: a $100 bankroll over 30 bets at about 1.85 each, needing 16 winners.

• Target: $165.28 — a profit of $65.28, 1.653 times the bankroll
• First stake: $12.72
• Chance of reaching the target at the odds' implied probability: 60.50%

Up to 14 losses are allowed; the 15th makes 16 wins impossible and the $100 is gone. Four times in ten, at the bookmaker's own prices, that is how the series ends.

Example 2 — 5 bets, 3 wins at even money

$100, five bets at 2.00 (+100), three of them must win.

• Target: $200.00; first stake $37.50
• Bet 1 wins: the bankroll is $137.50. Bet 2 loses: back to $100.00
• Next stake (bet 3): $50.00 — two wins are still needed from three bets
• Chance of reaching $200 at even money: 50.00%

If bets 3 and 4 also lose, the series has used its two allowed losses and the plan has staked everything that is left — exactly the point where a martingale would also be all in.

Example 3 — the bookmaker's margin

Ten bets at 1.90 (−111), six wins needed, $100. Prices of 1.90 on a coin-flip market imply 52.6%, but the true chance is 50%: the gap is the bookmaker's margin.

• Target: $225.65, first stake $30.43
• Chance at the odds' implied probability: 44.32%
• Chance at the true 50%: 37.70%
• Expected result of the series: −$14.94

Nothing in the staking plan can close that gap — only better prices or better picks can. The bankroll management calculator shows the steadier alternative of flat stakes.