Two video-poker games can have almost the same theoretical return and still produce very different bankroll experiences. One may return more value through frequent low and medium hands. Another may push more of its return into rare four-of-a-kind bonuses or the royal flush. Variance is the mathematical measure that captures how widely the game’s outcomes spread around their expected value.
RTP and variance therefore answer different questions:
- RTP / expected return: Where is the long-run average?
- Variance: How widely can individual results deviate from that average?
- Standard deviation: What is the spread expressed in the original unit scale rather than squared units?
A high-RTP game can have high variance. A lower-RTP game can have lower variance. One number does not determine the other.
Start with one wager and define the result consistently
Let X represent the net result per unit wagered on one completed hand.
For example:
- a complete loss gives
X = -1; - getting exactly the original stake back gives
X = 0net; - a result returning three units total gives
X = +2net profit.
Using net results avoids mixing “amount returned” with “profit.” Once the outcome values and probabilities are defined consistently, expected value is:
μ = E[X] = Σ pᵢxᵢ
where pᵢ is the probability of outcome i and xᵢ is its net result.
Variance is:
Var(X) = Σ pᵢ(xᵢ - μ)²
Standard deviation is:
SD(X) = √Var(X)
Variance squares the distance from the mean. That makes rare outcomes far from the average especially influential.
A simplified distribution shows why a rare premium hand dominates the spread
Consider an illustrative game with this deliberately simplified one-unit distribution. It is not a real paytable; it exists only to show the calculation.
| Net result | Probability | Contribution to EV |
|---|---|---|
| -1 | 70.0% | -0.700 |
| +1 | 25.0% | +0.250 |
| +4 | 4.9% | +0.196 |
| +250 | 0.1% | +0.250 |
The probabilities sum to 100%.
Expected value is:
μ = -0.700 + 0.250 + 0.196 + 0.250 = -0.004
So the theoretical net loss is 0.004 units per unit wagered. Expressed as return, the simplified model has a theoretical RTP of 99.6%.
Now apply the variance formula. The rare +250 outcome sits extremely far from the mean, so its squared distance contributes heavily even though its probability is only 0.1%.
For this distribution:
Var(X) ≈ 64.234
and:
SD(X) ≈ 8.015 units per hand
The expected loss is only four-thousandths of a unit, while the one-hand standard deviation is more than eight units. That is not a contradiction. Expected value measures the center; standard deviation measures spread around the center.
RTP can look excellent while short-term results remain severe
Suppose two games both return around 99.5% with correct strategy. Game A pays much of its value through frequent pairs, two pairs, straights, flushes, and ordinary quads. Game B transfers more of its total return into rare premium quads and a large royal-flush award.
Their long-run averages can be similar, but Game B can produce longer drawdowns and sharper jumps because more value depends on infrequent high-paying categories.
This is why the video poker RTP page and the video poker volatility page should be read together. RTP describes the mathematical destination over a very large sample under stated assumptions. Variance describes how uneven the path can be.
The royal flush matters because it is both valuable and rare
In many conventional video-poker paytables, the maximum-credit royal flush contributes a meaningful portion of theoretical return while occurring infrequently. A player can therefore play correctly for thousands of hands without receiving one.
During such a sample, the observed return can sit well below the published theoretical return because one rare, high-value category has not appeared. That does not mean the machine owes a royal, is “behind,” or has become more likely to produce one. It means the sample has not yet included that outcome.
The same principle applies to games with enhanced four-of-a-kind awards. Double Bonus and Double Double Bonus families, for example, can place more return into premium quads than a typical Jacks or Better schedule. The exact comparison depends on the exact paytable and strategy, not merely the game name.
Paytable changes can alter both the mean and the variance
Changing one payout can affect more than RTP.
Imagine two otherwise identical games. In one, a particular rare hand pays 200 units. In the other, it pays 400 units while some frequent lower award is reduced enough to keep total RTP close to the original level.
The second version has moved more value into a distant rare outcome. Even if the expected returns remain similar, the second-moment calculation changes and variance can rise substantially.
That is why “99.5% video poker” is not a complete volatility description. You need the full paytable and the strategy used to generate the outcome probabilities.
Strategy changes the outcome distribution, not only the average return
Video poker is unusual among casino machine games because the player’s hold/discard decisions affect the distribution of final hands.
A poor hold can reduce expected value. It can also alter variance. For example, abandoning a made paying hand to chase a rare premium result can shift probability away from frequent modest returns toward a much less likely large award. Another error might reduce both average return and variance.
So “I like high variance” is not a mathematical reason to make incorrect holds. The useful comparison is between correctly played paytables or strategies designed for the specific game.
Research on optimal video-poker decisions treats each initial hand through conditional expected values rather than intuition. The UNLV paper Optimal Conditional Expectation at the Video Poker Game Jacks or Better shows the decision structure behind this kind of analysis.
Standard deviation grows with the square root of independent hand count
If successive hands can be treated as independent and identically distributed with one-hand variance σ², then for n hands:
Var(total) = n × σ²
and:
SD(total) = √n × σ
Using the illustrative one-hand standard deviation of 8.015 units:
- over 100 independent hands, session SD ≈
√100 × 8.015 = 80.15units; - over 400 hands, session SD ≈
√400 × 8.015 = 160.30units.
The number of hands quadrupled from 100 to 400, but standard deviation only doubled because of the square-root relationship.
Expected result, by contrast, scales linearly with the number of hands. At μ = -0.004:
- 100 hands have expected result
-0.4units; - 400 hands have expected result
-1.6units.
This demonstrates why short-session actual results can dwarf the expected loss even when the game’s long-run mathematical disadvantage is small.
Multi-hand video poker needs covariance, not a blind independence assumption
Multi-hand games create an important complication. Several hands may begin from the same initial deal and then draw independently from related deck states according to the game design. Because the hands share initial information, treating every hand as completely independent can misstate total variance.
For a sum of correlated results:
Var(X₁ + X₂ + ... + Xₙ)
includes both the individual variances and covariance terms between hands.
That does not make multi-hand play mysterious; it means the simple n × variance shortcut requires the independence assumption. When outcomes are correlated, the dependence structure matters.
For practical bankroll discussion, this is enough to remember: five-play or ten-play video poker can expose several wagers per deal and can produce swings that are not captured accurately by pretending each displayed hand is an unrelated single-play session.
Dollar volatility scales directly with the amount wagered
Variance is often quoted in unit terms. Your bankroll experiences dollars.
Suppose a game’s standard deviation is 5 units per hand.
- At $1 total wagered per hand, one SD is $5.
- At $5 total wagered per hand, one SD is $25.
- At $25 total wagered per hand, one SD is $125.
The underlying unit variance can be identical while the financial effect changes in direct proportion to wager size.
This is why denomination and number of hands matter so much. Moving from single-hand quarter play to multi-hand dollar play changes actual money exposure even if the mathematical paytable is unchanged.
Variance is not a bankroll guarantee
A statement such as “this game has variance 20” does not tell you that a particular bankroll is safe. To estimate risk of ruin, you also need assumptions about:
- starting bankroll;
- wager size;
- number of hands or stopping rule;
- game expectation;
- outcome distribution;
- acceptable probability of failure;
- strategy consistency.
Variance is an input to risk analysis, not a complete bankroll prescription.
It is also not a promise that results will stay within one or two standard deviations. Standard deviation describes a distribution; it is not a hard boundary around future outcomes.
A rare jackpot can make a short record look better than the underlying game
Players often understand the drought side of variance but overlook the opposite distortion. A royal flush or premium quad can push a short observed return far above theoretical RTP.
A player who hits a royal in the first few hundred hands did not prove the machine returns 130%, just as a player who misses royals for 20,000 hands did not prove it returns 90%. Both samples can be heavily influenced by rare categories.
This is why actual session return should not be reverse-engineered into a new machine RTP.
Variance, volatility, hit frequency and RTP should remain separate concepts
These four ideas overlap in conversation but answer different questions:
| Measure | Main question |
|---|---|
| RTP | What percentage of wagered value is returned in the long-run theoretical model? |
| House edge | What is the complementary long-run casino advantage under the stated model? |
| Hit frequency | How often does the game produce an outcome defined as a hit or paying hand? |
| Variance | How widely do outcome values spread around expected value? |
| Standard deviation | What is that spread in the original unit scale? |
A game can hit often and still have high variance if some outcomes are very large and others small. A game can hit less often yet have moderate variance if its top awards are less extreme. Only the full probability-and-payout distribution settles the question.
Use variance to compare risk profiles, not to predict the next hand
The best practical use of video-poker variance is comparison. It helps explain why two good paytables can require different bankroll tolerance, why rare-hand droughts can dominate short records, and why a high RTP should never be interpreted as a smooth return schedule.
It does not identify when a royal is due, whether the next hand is likely to be a winner, or how much a particular session will lose.
For the complete picture, combine this page with video poker RTP, video poker house edge, video poker volatility, and strategy truth. The variance simulator can illustrate possible paths, but simulation should be read as a distribution exercise rather than a forecast of the next hand.