Donald-Nathanson System

This betting system was created by Thomas Donald for games with double payouts, like Roulette, Baccarat, and others. The idea is based on the assumption that wins and losses happen about equally. Later, mathematician Lev Nathanson improved the system. His version looks more natural and practical.

Thomas Donald’s System

Start with 1 base bet on your chosen side (for example, red). After each spin:

• If you lose, increase your bet on the same side by 1.
• If you win, decrease your bet on the same side by 1.

If your bet was 1 and you win, lower it by 1 to 0. Then, skip the next spin and bet nothing.

Nathanson’s Modification

Donald’s system did not handle the situation when you win with a 0 bet. Lev Nathanson suggested a solution. If you win at 0, bet 1 on the opposite side (-1 on the original side).

For example, you bet 0 on red and red wins. Then, your next bet is 1 on black.

This version works well when the same outcome repeats 2–4 times. It also handles longer streaks better than Martingale.

But you should reset the bet back to 1 from time to time. Otherwise, losses can become very large.

Also, there is no point in betting both sides at once. Over time, the bets will even out, and you will just move bets slightly between them.

However, you can bet on two different pairs. For example, red/black and odd/even at the same time.

Here is a quote from the book Roulette by Dmitry Lesnoy and Lev Nathanson:

“It is easy to prove: if out of 2N roulette spins, red and black appear N times each, you win N base bets. No matter how reds and blacks are ordered, the total win stays the same.”

Suppose roulette spins 36 times. Your results will look like this:

Red hits	14	15	16	17	18	19	20	21	22	23
利益	-22	-6	+6	+14	+18	+18	+14	+6	-6	-22

You apply the Donald-Nathanson strategy. Spin the roulette 36 times and compare the results. Count zero as black if you bet red, or as red if you bet black.

How to Use the Donald-Nathanson System in Crash

The Donald-Nathanson system fits Crash very well because you get double payouts for hitting your cashout target. Follow these steps:

1. Set a small cashout multiplier, like 2x. Stick to it every round.
2. Start with your base bet, for example $1.
3. If you crash before 2x (loss), add $1 to your next bet.
4. If you cash out at 2x (win), subtract $1 from your next bet.
5. If you win and your bet was $1, reduce by $1 to $0. Skip one round.
6. If you win while betting $0 (you skipped), bet $1 on the next round.
7. Always check your bets and reset to $1 after long win or loss streaks.
8. Never change your cashout target during the session.

This method works best in short sessions of 30–50 rounds. It helps balance wins and losses slowly without big jumps.

System Analysis

The Donald-Nathanson system uses simple arithmetic: 1, 2, 3, and so on. Each loss leads to a bigger bet by 1.

It works if wins and losses happen equally often. But in real games, outcomes are never perfectly balanced.

例えば

• In 10 spins, you might get 3 reds and 7 blacks.
• This is 30% to 70% — a 40% gap in percentage, but just 4 spins in number.
• After 100 spins, you could get 40 reds and 60 blacks.
• Now the percentage gap is smaller (20%), but the numeric gap is 20.

In that case, you would lose (1+2+3+…+20) = 210 bets.

That is why Donald-Nathanson works well for short sessions but needs a reset for long games.

長所

• The bet size grows slowly compared to systems like Martingale.

短所

• On long sessions, the system can cause big losses.

Tip:
Always reset your bet to the base amount after a long streak to keep the Donald-Nathanson system safe and stable.