Kelly vs Flat Betting: Which Is Better?
🛠️ Tools & FeaturesTwo main approaches to bet sizing: Kelly (proportional to edge) and flat (same amount every bet). Here's when each works best.
Flat Betting
Rule: Bet 1 unit ($50) on every play, regardless of edge size.
Pros:
• Simple — no math required
• Low variance — every loss is the same size
• Hard to blow up your bankroll
Cons: • Inefficient — you bet the same on a 2% edge as a 6% edge • Slower bankroll growth • Doesn't compound winners [/example]
Kelly Betting
Rule: Bet proportionally to your edge (bigger edge = bigger bet).
Pros:
• Mathematically optimal growth rate
• Bigger bets on better opportunities
• Compounds wins automatically
Cons: • Requires accurate edge estimates • Higher variance • More complex to implement [/example]
The Verdict
For most SharpWire users, Quarter Kelly is the sweet spot: you get the benefits of proportional sizing with variance closer to flat betting.
Practical compromise:
• Base unit: 1% of bankroll (flat component)
• Multiply by edge confidence:
- Low confidence edge: 0.5x (half unit)
- Normal edge: 1x (one unit)
- High edge + signal: 1.5-2x (bigger bet)
The Kelly Calculator on every game page shows Quarter, Half, and Full Kelly amounts. Most users should stick with Quarter Kelly. Track results in the Bet Tracker to see which sizing approach works for you over time.