The Lab · interactive

The near-miss effect: how reel weighting produces 'so close'

Predict whether a near-miss means a win is getting closer, then spin a three-reel demo and count near-misses against real wins. You will see how reel weighting, not luck, decides how often 'so close' appears.

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How it works

The three reels spin independently. Reels 1 and 2 put the diamond on the payline 42% of the time each. Reel 3 is weighted: the diamond lands on the line 4% of the time and just above or below it 58% of the time. A jackpot needs all three on the line: 0.42 × 0.42 × 0.04, about 0.71% or 1 spin in 142. A near-miss needs the first two on the line and the third beside it: 0.42 × 0.42 × 0.58, about 10.2% or 1 spin in 10. Near-misses therefore outnumber wins by 0.58 ÷ 0.04, or 14.5 to 1.

After the prediction, press Spin for one result or 'Auto ×100' for a hundred. Each reel shows the row above, the payline between the arrows and the row below, and a verdict labels the spin as a jackpot, a near-miss or a plain loss. Counters track spins, near-misses and real wins. After 20 spins a line reports how many near-misses the machine has served per win; it reads '∞' until the first jackpot, and about half of all 100-spin runs contain none. 'Show the trick' reveals reel 3's weighting: 58% beside the line, 4% on it.

A near-miss feels like progress, but it is a loss, and the next spin starts from the same odds. In a 2009 brain-imaging study, near-misses felt less pleasant than full misses yet raised the desire to play, an effect limited to trials where participants had personal control over arranging the gamble, and they recruited striatal and insula circuitry that also responded to wins. Rules address the design: Ontario's standard caps top-award symbols on single-line reel games at 12 appearances beside the payline, on average, for each one on it, and Great Britain's RTS 7C bans substituting a losing outcome with a near-miss.

What it leaves out: It is a single-line, three-reel demo with invented weights and no prize other than the jackpot, so it shows how often near-misses occur, not how they feel or change behaviour. Meant for adults (18+) as an educational model, it cannot alter the edge or the reel weighting of any real machine.

Sources

Checked on 2026-11-05. Independent, not affiliated. 18+.

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