Why “Raise the Stake After a Loss” Doesn’t Work: Martingale Maths Explained

“Chasing” a loss by raising the next stake sounds tidy: one win should wipe out the previous losses and leave a small profit. Martingale is the best-known version of that idea, and it still circulates in 2026 because it is easy to remember and feels disciplined. The problem is that casino games are built around probability, limits, and negative expectation. Once you put real numbers on the table, Martingale stops looking like a safety net and starts looking like a slow method for loading risk onto a single bad streak.

What Martingale actually does to your risk (not your luck)

Martingale is simple: pick an even-money bet (for example, red/black in roulette), start with a base stake, and double after every loss. When you finally win, you recover all previous losses and make one unit of profit (your original base stake). That is the sales pitch, and it’s mathematically true in a narrow sense: if you can keep doubling forever with no limits and infinite funds, a win will eventually arrive and it will net that one unit.

In real play, the system shifts the whole session’s result onto whether you meet a losing streak before you hit a limit. You are not improving the chance of winning the next spin. You are increasing the size of the next spin. That difference matters: roulette spins are independent, so the wheel does not “owe” you a red because you have seen five blacks in a row. The chance of red stays the same on every spin, no matter what happened ten seconds earlier.

The practical meaning is blunt: Martingale trades frequent small wins for rare, very large losses. Many sessions will end with a modest profit that looks steady. Then one long losing run arrives and wipes out a huge chunk of bankroll in minutes. The system does not remove risk; it concentrates risk.

A concrete roulette example with real numbers

Take European roulette (single zero), which is still common across Europe. On an even-money bet like red/black, you win on 18 numbers and lose on 19 (because of the zero). So the probability of losing one spin is 19/37, about 51.35%. The “house edge” comes from that extra losing number, and it does not disappear because you change your stake size.

Now start with £10 and use strict doubling. The stakes look like this: £10, £20, £40, £80, £160, £320, £640… After six consecutive losses you have already staked £10+£20+£40+£80+£160+£320 = £630, and the next bet is £640 just to try to win £10. Even if your bankroll can handle it, many tables simply cannot: maximum stakes exist specifically to prevent unlimited doubling.

How often do six losses in a row happen? The probability is (19/37)^6, roughly 1.83%. That sounds small until you remember you can play hundreds of spins in a sitting. Over a long session, “rare” streaks turn into “sooner or later” events. The deeper you go into a doubling ladder, the more your session depends on a single spin landing your way before your cash or the table limit runs out.

Expected value: why the house edge still wins, even if you “usually” profit

Casino games with a built-in edge have negative expected value for the player. That is not a moral judgement; it is the pricing model. If an even-money roulette bet has a house edge of about 2.7% on a single-zero wheel, the long-run expectation is that you lose roughly 2.7% of the total amount you wager, not 2.7% of your initial bankroll and not 2.7% of your last bet.

Martingale increases the total amount you wager during losing runs. In other words, it often increases the volume of action you put through a negative-expectation game. A session that “ends up £10” after a few steps can still involve hundreds of pounds cycled through the wheel. The bigger your total stake volume, the more the house edge has room to work.

This is why Martingale can feel convincing in short samples. Small wins arrive frequently, and they are visible. The cost is mostly hidden in risk: when the losing run arrives, the loss is not “unlucky”, it is the predictable tail of the distribution that the system forces you to face with inflated stakes.

“But I only need one win” is the trap

It is true that a win at the right moment resets the sequence and locks in a small profit. The trap is that the profit per completed cycle stays tiny while the downside grows fast. Your upside for surviving a six-loss sequence is still £10 (or whatever your base unit is). Your downside for failing that sequence is the full amount you could not cover — and that gap widens every step.

People often describe Martingale as “high probability”. A more accurate phrase is “high frequency of small wins”. That is not the same as safety. A strategy can show many winning sessions and still be a poor bet overall because the occasional losing session is catastrophic relative to the typical win.

There is also a behavioural cost: doubling makes it emotionally harder to stop. After three or four losses, your next bet no longer feels like “a stake”, it feels like “recovery”. That mental framing pushes players to ignore budgets, extend sessions, and take risks they would reject at the start. The system is designed around that pressure point.

Real-world constraints: bankroll limits, table limits, and time

Martingale relies on the ability to keep doubling. In reality you have three ceilings: your bankroll, the table maximum, and your tolerance for volatility. The first two are objective and often hit sooner than people expect. The third is personal, but it matters because stress changes decision-making, and chasing systems are stress machines.

Bankroll maths is unforgiving. If your base bet is £10 and the table maximum is £500, you can only double a limited number of times before you cannot place the next required stake. Even without a table limit, your own balance becomes the limit. A few extra steps in the ladder multiply required funds very quickly, and the “one more spin” mindset appears right when the risk is at its highest.

Time is a ceiling too. The longer you play, the higher the chance you will encounter an extreme streak. This is not superstition; it is probability. A person who stops early might bank a small profit and feel the system “worked”. A person who keeps going is giving the distribution more time to deliver the bad run that the system cannot handle.

Table limits are not a minor detail — they are the point

Casinos use minimum and maximum limits to manage risk, including the risk posed by doubling systems. If a wheel allows £5–£500 on outside bets, that range is not random. It sets the maximum number of consecutive losses a Martingale player can survive starting from £5. Once you hit the ceiling, the strategy breaks: you cannot place the required bet, so you cannot guarantee recovery on the next win.

Even when you are below the maximum, doubling makes your play profile obvious. That matters online and in land-based venues. You might see limits adjusted, offers restricted, or play flagged as high-risk behaviour. Regardless of any policies, the core issue stays the same: limits turn Martingale from “eventually I win” into “eventually I face a streak I cannot pay for”.

If you want a practical rule of thumb for 2026, it is this: any system that claims to “guarantee” a small profit in a negative-expectation game is quietly hiding an assumption about unlimited money or unlimited stakes. Remove that assumption, and the guarantee vanishes.