Lucky 15 and Lucky 31 bets: how many bets and what is the stake?
A Lucky 15 is 15 bets on 4 selections: 4 singles, 6 doubles, 4 trebles and 1 fourfold. A Lucky 31 is 31 bets on 5 selections. Total stake = unit stake x number of bets, so a KES 20 unit costs KES 300 on a Lucky 15 and KES 620 on a Lucky 31.
What a Lucky 15 and a Lucky 31 are
Both are full-cover bets that include the single bets. A Lucky 15 uses 4 selections and a Lucky 31 uses 5, and each selection is covered on its own and in every combination with the others. If you have read about the Trixie and Yankee, the only structural difference is that these two keep the singles.
Names vary between operators, and a bet called a Lucky 15 on one slip may be labelled differently on another. Count the lines listed on the slip rather than relying on the name.
How the bets are counted
One combination of k selections out of n is one bet. The number of different groups of k that can be drawn from n selections is written C(n, k). The total number of bets is the sum of C(n, k) for every k from 1 up to n.
For four selections: C(4, 1) = 24 ÷ (1 × 6) = 4 singles. C(4, 2) = 24 ÷ (2 × 2) = 6 doubles. C(4, 3) = 24 ÷ (6 × 1) = 4 trebles. C(4, 4) = 1 fourfold. So 4 + 6 + 4 + 1 = 15 bets.
For five selections: C(5, 1) = 5, C(5, 2) = 120 ÷ (2 × 6) = 10, C(5, 3) = 120 ÷ (6 × 2) = 10, C(5, 4) = 120 ÷ (24 × 1) = 5 and C(5, 5) = 1. So 5 + 10 + 10 + 5 + 1 = 31 bets.
| Selections | Singles | Doubles | Trebles | Fourfolds | Fivefolds | Sixfolds | Total bets |
|---|---|---|---|---|---|---|---|
| 4 (Lucky 15) | 4 | 6 | 4 | 1 | 0 | 0 | 15 |
| 5 (Lucky 31) | 5 | 10 | 10 | 5 | 1 | 0 | 31 |
| 6 | 6 | 15 | 20 | 15 | 6 | 1 | 63 |
The totals follow a pattern. Each selection is either in a given bet or not, which gives 2 × 2 × 2 × 2 = 16 choices for four selections, and removing the empty choice leaves 16 − 1 = 15. For five selections it is 2^5 − 1 = 31, and for six it is 2^6 − 1 = 63.
Finding the total stake
The stake you enter is the unit stake, and it is placed on every bet. The slip then shows a larger total, and that total is the amount that leaves your balance.
| Unit stake | Lucky 15 (15 bets) | Lucky 31 (31 bets) |
|---|---|---|
| KES 20 | KES 300 | KES 620 |
| KES 50 | KES 750 | KES 1,550 |
| KES 100 | KES 1,500 | KES 3,100 |
To work backwards, divide your ceiling by the number of bets. A ceiling of KES 1,000 allows a unit stake of at most 1,000 ÷ 15 = KES 66.67 on a Lucky 15, which is KES 66 in whole shillings. On a Lucky 31 it is 1,000 ÷ 31 = KES 32.26, which is KES 32.
Illustrative example: a Lucky 15
Illustrative example
Four invented selections at decimal odds A = 2.00, B = 3.00, C = 1.50 and D = 4.00, with a unit stake of KES 20. Total stake = 20 × 15 = KES 300. The odds of a combination are the product of its legs, as set out in the guide on accumulator odds and payout.
| Group | Bets and odds | Sum of odds |
|---|---|---|
| 4 singles | A 2.00, B 3.00, C 1.50, D 4.00 | 10.50 |
| 6 doubles | AB 6.00, AC 3.00, AD 8.00, BC 4.50, BD 12.00, CD 6.00 | 39.50 |
| 4 trebles | ABC 9.00, ABD 24.00, ACD 12.00, BCD 18.00 | 63.00 |
| 1 fourfold | ABCD 36.00 | 36.00 |
All four winning pays 20 × (10.50 + 39.50 + 63.00 + 36.00) = 20 × 149 = KES 2,980, a result of 2,980 − 300 = +KES 2,680. A quick check: add 1 to each selection's odds to get 3, 4, 2.5 and 5. Their product is 3 × 4 × 2.5 × 5 = 150, and 150 − 1 = 149, the same sum of odds.
What each outcome returns
The return depends on which selections win, because only bets with no losing leg pay. Using the same invented selections:
| Winners | Bets that win | Sum of odds | Total return | Result after KES 300 |
|---|---|---|---|---|
| A, B, C and D | all 15 | 149.00 | KES 2,980 | +KES 2,680 |
| A, B and C | 3 singles, 3 doubles, 1 treble | 29.00 | KES 580 | +KES 280 |
| A and C only | 2 singles, 1 double | 6.50 | KES 130 | −KES 170 |
| B only | 1 single | 3.00 | KES 60 | −KES 240 |
| C only | 1 single | 1.50 | KES 30 | −KES 270 |
| None | none | 0.00 | KES 0 | −KES 300 |
For the A, B and C row: singles 2.00 + 3.00 + 1.50 = 6.50, doubles 6.00 + 3.00 + 4.50 = 13.50, treble 9.00, and 6.50 + 13.50 + 9.00 = 29.00. The check 3 × 4 × 2.5 − 1 = 29 agrees. One winner leaves a loss here because the single pays only its own odds against a stake spread over 15 bets.
The A and C row gives 2.00 + 1.50 + 3.00 = 6.50, so 20 × 6.50 = KES 130. Two winners out of four is a loss of KES 170 in this example.
Lucky 31 in the same way
Add a fifth invented selection E at 2.50 to the four above, so its unit-return factor is 3.5. If all five win, the sum of odds is 3 × 4 × 2.5 × 5 × 3.5 − 1 = 525 − 1 = 524. With a unit stake of KES 20 the total return is 20 × 524 = KES 10,480 against a total stake of 20 × 31 = KES 620.
One extra selection took the stake from KES 300 to KES 620, more than double. The top return needs every selection to win together, and the chance of that is the product of their probabilities, covered in the chance of winning an accumulator.
Why more lines do not remove the margin
Every price carries the bookmaker's margin, and each double, treble and fourfold multiplies several of those prices together. The average result of the whole slip is the sum of the average results of its lines, so lines that each cost money on average still cost money in total. Splitting a stake over 15 or 31 bets spreads the outcomes without lowering the cost per shilling.
The KES 20 floor and combination bets
Section 71(1) of the Gambling Control Act, 2025 says a player in an online gambling activity shall not bet an amount of less than twenty shillings in a competition. The minimum online stake entry sets the section out. The Act does not say whether each line of a Lucky 15 or Lucky 31 is a separate bet for this purpose, so this guide states no rule where the Act is silent. The operator's displayed terms say what unit stake is accepted.
Before you place one
- Count the lines on the slip and confirm that unit stake × bets equals the total shown.
- Write down the total stake first and compare it with the ceiling in your betting budget and limits.
- Work out the return for one and two winners, not only for all winners, because those outcomes are common.
Gambling is addictive. Play responsibly.
Questions and answers
How many bets are in a Lucky 15?
Fifteen. With four selections there are 4 singles, 6 doubles, 4 trebles and 1 fourfold, and 4 + 6 + 4 + 1 = 15.
How many bets are in a Lucky 31?
Thirty-one. With five selections there are 5 singles, 10 doubles, 10 trebles, 5 fourfolds and 1 fivefold, and 5 + 10 + 10 + 5 + 1 = 31.
What is the difference between a Lucky 15 and a Yankee?
Both use four selections, but a Yankee leaves out the four singles. A Yankee is therefore 11 bets and a Lucky 15 is 11 + 4 = 15 bets.
Can a Lucky 15 return less than the total stake with one winner?
Yes. With one winner only that selection's single pays, and it returns the unit stake times its odds. Unless those odds are at least the number of bets (15), the return is smaller than the total stake.
How do I find the bets for six selections?
Add the combinations of every size from 1 to 6: 6 + 15 + 20 + 15 + 6 + 1 = 63. The shortcut is 2 to the power of n, minus 1, which gives 2^6 - 1 = 63.
Does the KES 20 online minimum apply to each line of a Lucky 15?
Section 71(1) of the Gambling Control Act, 2025 says a player in an online gambling activity shall not bet an amount of less than twenty shillings in a competition. The section does not say how the lines of a combination bet are counted, so check the operator's displayed terms for the minimum unit stake.
Sources
- Gambling Control Act, 2025 (No. 14 of 2025), s.71(1), accessed 2026-10-19