Expected loss per hour: how bet speed multiplies the house edge

The average cost of an hour at a casino game is the number of bets in that hour, multiplied by the average stake, multiplied by the house edge. Doubling the speed doubles the cost, even though the edge itself never changes. It is an average, so any single hour can end far above or below it.

By Nairobi Ultimate Editorial (prepared with AI tools under our editorial policy) · Last updated 2026-10-30

The formula

A house edge tells you the average share of each stake that the game keeps. To turn that into a cost per hour, count how much money passes through the game in that hour.

Expected loss per hour = bets per hour × average stake × house edge

The first two terms give the total staked. The edge is the rate applied to it. The idea behind the rate is expected value, and the edge itself is explained in the guide to how RTP and house edge work.

Step 1: get the edge from the rules

Take a single-zero roulette wheel. It has 37 pockets: the numbers 1 to 36 and one zero. A KES 100 bet on red wins on 18 pockets and loses on the other 19, and a win pays 1 to 1.

The derivation for every bet on the wheel is in the guide to the roulette house edge.

For a second case, suppose a game has a return to player (RTP) of 96%. This is an assumption chosen for arithmetic, not a claim about any real game. The edge is then 100% − 96% = 4%, or KES 4 per KES 100 staked.

Step 2: multiply by the number of bets

Pace varies widely between games. A live table with a human dealer usually runs fewer rounds per hour than a software game. The table below uses hypothetical paces of 60, 300 and 600 bets an hour, which are not measured figures for any game.

Each row works out total staked = bets × stake, then the loss at 4% (staked × 0.04) and at 1/37 (staked ÷ 37). Figures are in KES, rounded to the nearest cent.

Only the product of bets and stake matters. That is why 300 bets of KES 20 and 60 bets of KES 100 both stake KES 6,000 and cost the same on average, and why every figure doubles when either input doubles.

Why speed matters more than it looks

A player thinks in stakes: "it is only KES 20 a go". The edge works on the total staked, and a fast game turns small stakes into a large total.

The minimum online bet in Kenya is twenty shillings, set by section 71(1) of the Gambling Control Act, 2025. That floor says nothing about how many bets are placed per hour, so the hourly total is still in the player's hands.

It is an average, not a forecast

The formula gives the centre of a spread of possible results. Take 60 bets of KES 100 on red. The average is a loss of about KES 162, yet every single bet ends at +100 or −100, so a real hour can finish well ahead or several times worse than the average.

How wide the spread is depends on the game, a property measured by standard deviation. Over more bets the result tends to move toward the average, as the guide on theoretical RTP against actual short-session results shows. A good hour does not mean the formula is wrong, and it does not lower the next hour's cost.

Two further points follow from this:

• The expected loss never falls to zero while the edge is above zero. Only fewer bets or smaller stakes reduce it.
• Winnings are not set aside. Money won is staked again, so the total staked, and with it the cost, keeps growing as play continues.

How to estimate your own figure

1. Find the game's displayed house edge or average return. Licensees must show these under regulation 20(2) of the Conduct of Gambling Operations Regulations, 2026.
2. Estimate bets per hour from the pace of the game. Count rounds for a few minutes and scale up, or use the round count in the game history.
3. Take your usual stake. If it varies, use the total staked divided by the number of bets.
4. Multiply the three numbers. The result is the average cost of the hour, not a limit on it.

Limits that cap the total staked

Because the cost follows the total staked, controls on time and money act directly on it. Regulation 87 of the same Regulations says licensees must provide tools for deposit limits on a daily, weekly and monthly basis, loss, session and expenditure limits, reality checks that show the duration of play, and self-exclusion of at least twenty-four hours.

A session limit caps the number of bets, and a loss limit caps what a bad run can take. Setting them before play starts is easier than deciding in the middle of a streak, a point covered in the guide to the gambler's fallacy and session limits.

Gambling is addictive. Play responsibly, and treat any figure here as the price of entertainment, never as a way to make money.