The 5-Leg Dilemma: Balancing Risk and Reward
One of the most popular ticket sizes in sports betting is the 5-leg parlay. Picking five winners feels achievable, yet it offers a high enough cumulative odds multiplier to generate an exciting payout. However, experienced bettors know that hitting 5 out of 5 is statistically very difficult. The inevitable result is often a ticket that loses by just one or two legs.
To counter this frustration, bettors turn to system betting. When dealing with 5 selections, you are faced with a strategic decision: Should you play a System 3 (meaning you need 3 correct picks to win) or a System 4 (meaning you need 4 correct picks to win)?
In the UK, a System 3 is often referred to as betting on "Trebles," while a System 4 is betting on "4-Folds." In the US, they are variations of the Round Robin. Regardless of the terminology, the mathematical reality is the same. System 3 offers a larger safety net but costs more to place, while System 4 is cheaper but leaves less room for error.
In this article, we will conduct a detailed case study comparing these two popular systems. If you want to experiment with different odds and stake sizes for these systems yourself, we highly recommend using our System Bet Calculator.
The Case Study: Setting the Parameters
To ensure a fair and direct comparison between the two systems, we will use the exact same parameters for both scenarios.
- Total Selections (n): 5 Matches (Teams A, B, C, D, and E).
- The Odds: For simplicity, we will assume all 5 matches have exactly 2.00 (+100) decimal odds. This means each individual game is effectively a coin toss.
- Unit Stake: We will wager $10 per line (combination).
Now, let's break down the math, the costs, and the potential returns for both System 3 and System 4 under these exact conditions.
Scenario A: The System 3 (3 out of 5)
A System 3 prioritizes safety. You are telling the sportsbook that out of your 5 selections, you only need to get 3 correct to see a return. You are giving yourself a comfortable 2-game margin of error.
1. Cost and Combinations
The system will take your 5 teams and generate every possible 3-team combination.
- Combinations Formula: $C(5,3) = (5 \times 4 \times 3) / (3 \times 2 \times 1) = 10$ combinations (lines).
- Total Ticket Cost: 10 lines $\times$ $10 unit stake = $100 Total Cost.
2. Potential Returns (Payouts)
Because all our odds are 2.00, every single 3-team combination has identical odds: $2.00 \times 2.00 \times 2.00 = 8.00$. Therefore, every winning line pays out $80 (8.00 odds x $10 stake).
Let's look at how the payouts scale based on how many games you actually win:
- If you get 3 correct: You only have 1 winning line. You win $80. (Wait a minute! You spent $100 on the ticket, but only won $80. Despite "winning" the bet, you suffered a net loss of $20. This is the danger of System 3 with average odds!)
- If you get 4 correct: $C(4,3) = 4$ winning lines. 4 lines $\times$ $80 = $320. (A very solid $220 profit).
- If you get all 5 correct: All 10 lines win! 10 lines $\times$ $80 = $800 Maximum Return.
Scenario B: The System 4 (4 out of 5)
A System 4 is a more aggressive approach. You are confident in your picks and only need a 1-game margin of error. You must get at least 4 out of 5 correct to see any money.
1. Cost and Combinations
The system will take your 5 teams and generate every possible 4-team combination.
- Combinations Formula: $C(5,4) = 5$ combinations (lines).
- Total Ticket Cost: 5 lines $\times$ $10 unit stake = $50 Total Cost.
Notice that System 4 is exactly half the price of System 3!
2. Potential Returns (Payouts)
Again, since all odds are 2.00, every 4-team combination has identical odds: $2.00 \times 2.00 \times 2.00 \times 2.00 = 16.00$. Every winning line pays out $160 (16.00 odds x $10 stake).
Let's look at the payout scale:
- If you get 3 correct: Zero lines win. You lose your entire $50 investment.
- If you get 4 correct: You have exactly 1 winning line. You win $160. (You spent $50 and won $160, securing a handsome $110 net profit).
- If you get all 5 correct: All 5 lines win! 5 lines $\times$ $160 = $800 Maximum Return.
The Verdict: Which System is Better?
When you place System 3 and System 4 side-by-side using the exact same $10 unit stake, some fascinating mathematical realities emerge.
- The Cost Factor: System 3 is significantly more expensive to play ($100 vs $50). If you are on a tight bankroll, System 4 is the clear winner.
- The Maximum Return: Interestingly, if you hit all 5 games perfectly, both systems pay out exactly $800. You don't get a higher maximum ceiling for paying double the ticket price in System 3.
- The "3 Correct" Trap: The biggest revelation is what happens when you hit exactly 3 games. In System 4, you lose everything ($50). In System 3, you "win," but because the odds were only 2.00, the payout ($80) doesn't even cover the $100 ticket cost. You lose $20 anyway.
When to Play System 3 vs. System 4
Choose System 4 if: Your average odds are around 2.00 (+100) or lower. System 4 is cheaper to play, and if you hit the required 4 games, it guarantees a strong profit. Paying double for a System 3 safety net that doesn't even cover your initial investment if you hit exactly 3 games is mathematically flawed.
Choose System 3 if: You are betting on heavy underdogs or draws where the average odds are much higher (e.g., 3.00 or +200). If your odds are 3.00, a single winning 3-team combination pays 27.00 odds. At $10 a line, that's $270. In that scenario, paying $100 for the System 3 ticket is highly profitable even if you only hit exactly 3 games.
Ultimately, the right choice depends entirely on the odds of the specific teams you have selected. Don't guess which system is better; prove it mathematically. Plug your selections into the System Bet Calculator and compare the total costs and theoretical returns before you lock in your bet.
