What one spin really looks like
Each layout: 18 numbers covered, 15 units used, 12 straight + 3 splits. This never changes.
The three outcomes
Straight hits: +21 units (35 payout + 1 chip back - 15 bets).
Split hits: +3 units (17 payout + 1 chip back - 15 bets).
Miss: -15 units. These three define the system.
The theoretical distribution
On a 37-number wheel, over a large sample: 19 spins miss all 18 numbers, 12 spins hit straight numbers, 6 spins hit splits.
If perfectly distributed over 37 spins: -15 units total. That's exactly the house edge — one full 15-unit bet lost every 36–37 spins.
Why real sessions feel different
Real play never looks like the average. Losses cluster. Wins cluster. You can miss many times in a row, or hit several times close together.
This is variance. Variance is why bankroll management exists.
Why 4 bets is the minimum
Bring at least 4 full bets — 4 × 15 = 60 units.
This allows room for short losing streaks without panic, time for variance to play out, and emotional stability.
The goal is not to beat the math. The goal is to survive the math.