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A round robin is a betting system that creates multiple parlays from a selection of picks, covering all possible combinations of a specific size. For example, selecting 4 games and choosing 2-team parlays generates 6 separate bets covering every possible 2-team combination. Round robins provide insurance against one or two losing picks while maintaining higher potential payouts than straight bets.
Round Robin
A round robin generates multiple parlays from your selections, covering every combination of a chosen size. Instead of one all-or-nothing parlay, you get several smaller parlays that provide protection against individual losses. It's the middle ground between straight bets and full parlays—higher variance than singles, but much safer than putting all eggs in one basket.
Table of Contents
- How Round Robins Work
- Calculating Combinations
- Round Robin Math
- Strategy Guide
- When to Use Round Robins
- Common Configurations
How Round Robins Work {#how-it-works}
You select multiple games and choose a parlay size. The system creates every possible parlay combination of that size.
Example: 4 Picks, 2-Team Parlays
Your selections:
- A: Lakers -3 at 1.91
- B: Celtics ML at 1.75
- C: Over 210.5 at 1.87
- D: Warriors -5 at 1.95
Generated parlays (6 bets):
| Parlay | Legs | Combined Odds |
|---|---|---|
| 1 | A + B | 3.34 |
| 2 | A + C | 3.57 |
| 3 | A + D | 3.72 |
| 4 | B + C | 3.27 |
| 5 | B + D | 3.41 |
| 6 | C + D | 3.65 |
If betting $10 per parlay: Total stake = $60
Outcome Scenarios
All 4 picks win:
- All 6 parlays win
- Total return: ~$207 (profit: ~$147)
3 picks win, 1 loses (say D loses):
- Winning parlays: A+B, A+C, B+C (3 wins)
- Losing parlays: A+D, B+D, C+D (3 losses)
- Return: ~$102 (profit: ~$42)
2 picks win, 2 lose:
- Only 1 parlay wins (the two winners together)
- Return: varies based on which two win
- Usually a loss overall
1 or 0 picks win:
- Total loss of all bets
Calculating Combinations {#calculation}
Combination Formula
The number of parlays in a round robin:
Where:
- n = total picks
- k = parlay size
Common Round Robin Sizes
| Picks | Parlay Size | Number of Bets | Losses Protected |
|---|---|---|---|
| 3 | 2-team | 3 | 1 |
| 4 | 2-team | 6 | 1 |
| 4 | 3-team | 4 | 1 |
| 5 | 2-team | 10 | 1-2 |
| 5 | 3-team | 10 | 1 |
| 6 | 2-team | 15 | 1-2 |
| 6 | 3-team | 20 | 1 |
| 6 | 4-team | 15 | 1 |
| 8 | 2-team | 28 | 2-3 |
Full Round Robin
Some bettors create "full" round robins including multiple parlay sizes:
4 picks, full round robin:
- 6 × 2-team parlays
- 4 × 3-team parlays
- 1 × 4-team parlay
- Total: 11 bets
This maximizes potential returns but also stake required.
Round Robin Math {#math}
Expected Value Calculation
Each parlay in a round robin is independent. Total EV = sum of individual parlay EVs.
Example: 4 picks at -110, 2-team parlays
Each pick has implied probability 52.4% (after vig).
For each $10 parlay:
Total EV for 6 parlays: -$2.64 on $60 wagered (-4.4%)
Variance Comparison
| Bet Type | Total Stake | Max Win | EV | Variance |
|---|---|---|---|---|
| 4-leg parlay | $60 | $800 | -$5.40 | Very high |
| 4 straight bets | $60 | $115 | -$2.76 | Low |
| 4-pick RR (2-team) | $60 | $207 | -$2.64 | Medium |
Round robin: Similar EV to straights, but higher upside.
Profit Probability
4 picks, 2-team round robin (assuming 50% win rate each):
| Wins | Probability | Net Outcome |
|---|---|---|
| 4/4 | 6.25% | +$147 profit |
| 3/4 | 25% | +$42 profit |
| 2/4 | 37.5% | -$27 loss |
| 1/4 | 25% | -$60 loss |
| 0/4 | 6.25% | -$60 loss |
Profit probability: 31.25% (vs 6.25% for 4-leg parlay)
Strategy Guide {#strategy}
Strategy 1: Optimal Configuration
| Your Style | Recommended Setup |
|---|---|
| Conservative | 3 picks, 2-team parlays (3 bets) |
| Balanced | 4 picks, 2-team parlays (6 bets) |
| Aggressive | 5 picks, 2-team parlays (10 bets) |
| High volume | 4 picks, 2&3-team (10 bets) |
Strategy 2: Stake Management
Unit-based staking:
| Total Budget | Per Parlay | Configuration |
|---|---|---|
| $30 | $10 | 3 picks, 2-team |
| $60 | $10 | 4 picks, 2-team |
| $50 | $5 | 5 picks, 2-team |
| $100 | $10 | 5 picks, 2-team |
Keep per-parlay stakes equal for simplicity.
Strategy 3: Selection Quality
Round robins don't improve bad picks. Requirements:
| Criterion | Why It Matters |
|---|---|
| All picks are +EV | Round robin multiplies your edge |
| Uncorrelated events | Correlation reduces protection value |
| Similar confidence | Weakest pick drags down ROI |
Don't include: "Lock of the century" with three questionable picks. The weak picks contaminate most parlays.
Strategy 4: Compare to Alternatives
Before placing round robin, calculate:
Option A: 4-pick round robin (2-team), $10 each
- Stake: $60
- Max profit: $147
- Profit if 3/4: $42
Option B: 4 straight bets, $15 each
- Stake: $60
- Max profit: $55
- Profit if 3/4: $13.65
Option C: 4-leg parlay, $20 + straight bets $10 each
- Stake: $60
- Max profit: $246
- Profit if 3/4: -$20 (lose parlay, win straights)
Choose based on your risk preference.
When to Use Round Robins {#when-to-use}
Good Situations
| Scenario | Why Round Robin Works |
|---|---|
| High-confidence picks | Protect against variance |
| Similar odds selections | Balanced parlay payouts |
| Entertainment value | Multiple action over single parlay |
| Hedging capability | Can hedge individual parlays |
Bad Situations
| Scenario | Why Avoid Round Robin |
|---|---|
| 1-2 weak picks included | Contaminate most parlays |
| Correlated legs | Protection is illusory |
| Very long odds picks | Parlays become unlikely |
| Small bankroll | Too many bets to manage |
Round Robin vs Full Parlay
| Factor | Round Robin Better | Full Parlay Better |
|---|---|---|
| Risk tolerance | Lower | Higher |
| Expected one loss | Yes | No |
| Want any profit | Yes | Want max profit |
| Uncertain about picks | Yes | Very confident |
Common Configurations {#configurations}
3 Picks, 2-Team Parlays (3 bets)
The simplest round robin. One loss = one winning parlay.
| Parlays | Odds Range* | Max Profit (per $10) |
|---|---|---|
| A+B | 3.3-3.7 | ~$34 |
| A+C | 3.3-3.7 | ~$34 |
| B+C | 3.3-3.7 | ~$34 |
*At -110 odds per leg
Outcomes:
- 3/3 wins: ~$72 profit
- 2/3 wins: ~$4 profit
- 1/3 or less: ~$30 loss
4 Picks, 2-Team Parlays (6 bets)
Most popular configuration. Good balance of protection and upside.
5 Picks, 2-Team Parlays (10 bets)
Maximum practical round robin. Protects against 2 losses.
| 5 Pick Results | Winning Parlays | Approximate Result |
|---|---|---|
| 5/5 | 10 | +$234 |
| 4/5 | 6 | +$100 |
| 3/5 | 3 | -$5 to +$10 |
| 2/5 | 1 | -$75 |
| 1/5 or less | 0 | -$100 |
Mixed Parlay Sizes
4 picks: 2-team and 3-team parlays (10 bets)
- 6 × 2-team parlays
- 4 × 3-team parlays
Higher upside, higher risk.
Round Robin Calculator {#calculator}
Quick Reference Table
$10 per parlay, -110 odds:
| Config | Bets | Stake | All Win | 1 Loss | 2 Losses |
|---|---|---|---|---|---|
| 3×2 | 3 | $30 | +$72 | +$4 | -$30 |
| 4×2 | 6 | $60 | +$147 | +$42 | -$27 |
| 4×3 | 4 | $40 | +$238 | -$40 | -$40 |
| 5×2 | 10 | $100 | +$234 | +$100 | +$1 |
| 5×3 | 10 | $100 | +$596 | +$169 | -$100 |
Common Mistakes {#mistakes}
Mistake 1: Including Weak Picks
One -EV pick ruins your edge on most parlays.
Mistake 2: Ignoring Total Stake
10-bet round robin at $10 each = $100 at risk. Size accordingly.
Mistake 3: Correlated Selections
Two picks from same game aren't independent—protection is false.
Mistake 4: Chasing Losses
Round robins don't recover losses faster—they're still negative EV if picks are bad.
Related Calculators
Round Robin Calculator - Generate all parlay combinationsParlay Calculator - Calculate individual parlay oddsAcca Insurance Calculator - Evaluate insurance offers
Frequently Asked Questions
Evgeniy Volkov
Fullstack developer with a background in mathematics. I build the calculators and game-style tools on ToolsGambling with Pixi.js and modern web tech, and every result uses transparent probability formulas you can verify yourself.
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