The new bankroll

What actually happens after a win

Four datasets, all from real betting records rather than laboratory tasks, point the same way. In 1,913,251 bets from 2,000 online casino players, the next bet after a win rose by about 3.4% per standard deviation of win size on slots and by 13.5% to 16.7% on blackjack and roulette Sci Rep 2024. In 565,915 online sports bets from 776 gamblers, the mean stake after a win was £18.47 against £10.89 after a loss, on a median stake of £14 overall Cognition 2014. Across 36,328 real sports betting accounts, a big win was followed by more engagement, more losses and more risk over the following weeks, with the effect declining over time Comput Hum Behav 2023. And watched directly on casino video, players placed more bets and covered more numbers after a win than after a loss J Risk Uncertain 2005.

One detail in the sports-betting data is worth keeping, because it is not the story people expect. Stakes went up after wins while the prices selected got shorter, not longer: more money on safer-looking bets Cognition 2014. That is not the same thing as recklessness, and it is still a size decision nobody made on purpose.

Why a share of the balance is the wrong rule here

Our normal sizing rule is a share: one unit is 1 to 2% of the bankroll, and no single position gets more than 5% (bankroll and units). That rule is written for a bankroll that changes slowly. A big win changes it in one step, and a percentage rule applied to the new balance raises the unit automatically, by exactly the amount of the win, without anyone deciding anything. The evidence above says size drifts upward after a win even without a rule helping it along.

So the order matters. Decide the bankroll figure first, as money, and only then apply the unit percentage to it. Not the other way around. The bankroll is the decision; the unit is arithmetic.

Write the number before you look at the balance

The most useful study of what individual practices go with less harm looked at 1,174 regular gamblers and focused on the 577 most susceptible to it PLoS ONE 2019. Nine practices came out of the analysis. Associated with lower harm: stopping when it is not fun any more, which had the strongest protective association; keeping a household budget; having a dedicated gambling budget; setting aside a fixed amount to spend when gambling; having other hobbies; and not playing when upset. Associated with higher harm: using credit or cash advances to play, which had the strongest harmful association; playing to make money or to add to your income; and believing a system or a strategy makes success certain.

Two of those are this page: a dedicated budget, and a fixed amount set aside before playing. Note honestly what is not on the list. Nobody has isolated “keep the winnings in a separate account” as an intervention and measured it, so the most we can say is that separating the money is consistent with what was measured about dedicated budgets. We are not going to upgrade that into a finding.

Note the second item on the harmful side too, because it points at us. Playing to add to your income was associated with more harm, not less, in that analysis. If the plan for the next bankroll is that it has to earn something, the plan is the problem and no size fixes it.

How the number gets entered changes the number

Limits set in advance do measurably move behaviour, in the group that needs it. Among the most intense 10% of 100,000 tracked players, setting a monthly cash-in limit brought theoretical loss down to 86% of the previous thirty days, and casino players setting a weekly limit came down to 77% J Gambl Stud 2013. The caution attached to that by a later synthesis is real and worth carrying: a limit can be read as a target, and for some players limits made things worse rather than better Addict Res Theory 2017.

The interface matters more than it should. A trial run with a large operator found that removing high preset options from a deposit-limit form cut the size of the limits people chose by an estimated 45%, and recommended a free text box with no suggested minimum or maximum BIT 2021. The practical version for a prediction market: type the figure in yourself, from a decision you already made, rather than picking whichever option is offered. Kalshi has funding caps and opt-outs in its Responsible Trading Hub Kalshi, and a cap set there is a limit that holds when you are no longer in the mood to hold it.

A break ends the run. It is not a cure

There is no study of a break taken specifically after a big win. What exists is a set of large trials of mandatory breaks in general, and they agree with each other. A one-month randomised trial with 12,510 players found longer breaks lengthened the time before the next session, and that after the trial the effect largely faded, persisting only for players who had taken more than nine fifteen-minute breaks Int J Ment Health Addict 2022. A British study of 2,021 players with a forced hour after a tenth same-day deposit found a large same-day effect, 32% continued depositing against 73% in the control period, and no significant difference the next day J Gambl Stud 2022. One review also notes that forced breaks increased craving in some laboratory settings IJERPH 2024.

So the honest claim is narrow and it is still worth having: a break is good at ending the run you are in, and it is not a character repair. Use it for what it does. The reset monitor is five minutes and stores nothing anywhere but your own device.

What this page will not do

It will not give you a split. There is no citable source for how a win divides between money to protect, money to put away and money to play with, so any ratio printed here would be ours and unsourceable, and a slider that turns a balance into three figures is advice wearing the costume of a tool. The split is yours to make, or a question for someone you pay to answer it.

It will not give you a figure either. A page that answers “how much should I keep playing with” with a number has told you what to risk. What it can do is insist the number exists, that you wrote it, and that you wrote it first.

When that figure is set, bankroll and units sizes the positions inside it, taking profits decides the exits, and tilt and loss limits is the stop rule for when a run turns. Back to after a big win for the other three moves.