What “value” means in sports betting
A bet has value when your estimated win probability is higher than the probability implied by the sportsbook’s odds. In other words, you’re paying less than the fair price. That’s the core of +EV (positive expected value) betting.
Step 1: Convert odds into implied probability
For American odds, convert the price into a percent chance:
- Positive odds +A → implied probability = 100 / (A + 100)
- Negative odds −A → implied probability = A / (A + 100), using A as the absolute value
Example: +150 implies 100 / (150 + 100) = 40%. −120 implies 120 / (120 + 100) ≈ 54.5%.
Step 2: Remove the vig (overround) to get “fair” odds
Books build margin into prices. Sum the implied probabilities for all mutually exclusive outcomes; anything above 100% is the overround (margin). To estimate “no-vig” probabilities, divide each outcome’s implied probability by the total sum. This gives a fair, margin-free baseline you can compare to your own model.
Step 3: Compare your edge and compute expected value
If your assessed probability exceeds the book’s no-vig probability, you have an edge. EV is the win probability times win return minus loss probability times stake. Using EV consistently (rather than gut feel) is fundamental to value betting.
Step 4: Use the closing line as a skill benchmark
Markets tend to be most efficient right before kickoff. If, over many bets, your average price beats where the market finally closes (positive CLV), that’s a strong signal you’re finding value, even though individual bets will still lose sometimes.
Practical ways to find value
Line shop against sharper, lower-margin books
Comparing multiple operators surfaces mispriced lines. Lower-margin “sharp” books help you gauge the true market price, making it easier to spot outliers elsewhere.
Monitor news and timing
Odds move on injury reports, weather, travel, and starting lineups. Acting before consensus reprices the market is a classic path to CLV.
Focus on markets you can model
Totals, player props, niche leagues, or live markets can be softer if you have better data or faster updates than the crowd — but always validate by tracking CLV and results.
Strip the juice before judging any “boost”
Many promos look generous but still carry margin. Convert to implied probability, remove the vig, and confirm the net EV.
Bankroll sizing that respects your edge
The Kelly Criterion prescribes an optimal fraction of bankroll to stake based on edge and odds; many bettors use “half-Kelly” or smaller to reduce volatility. The key is to scale stakes to your edge rather than betting flat amounts.
Crypto-specific factors that change the value equation
Volatility of your bankroll
If you hold BTC/ETH, your bankroll’s fiat value can swing between bet placement and payout, distorting realized EV. Stablecoins aim to reduce this by pegging to a reference asset (often USD), though they introduce issuer and peg risks.
Funding and settlement timing
On-chain transfers can take time to confirm (e.g., Bitcoin targets ~10-minute blocks; post-Merge Ethereum targets ~12-second slots). Slow deposits can cost you the price you wanted, so plan ahead when chasing lines.
Compliance and source-of-funds scrutiny
Licensed operators often treat crypto-sourced funds as higher risk and may ask for enhanced due diligence. Build this friction into your timing so you don’t miss numbers.
Worked example (moneyline)
- Book A posts Team X at +160 vs Team Y −175.
- Convert to implied probabilities: +160 → 38.5%; −175 → 63.6%. Sum = 102.1% (about 2.1% overround).
- No-vig probabilities: Team X ≈ 38.5/102.1 = 37.7%; Team Y ≈ 62.3%.
- Your model makes Team X 41%. Your edge ≈ 41% − 37.7% = 3.3 percentage points. That’s value; consider a stake sized to your edge.
Common mistakes that kill value
- Comparing your model to the book’s vigged number instead of no-vig.
- Chasing boosts without checking true price.
- Declaring victory after a single win; judge your process with CLV over many bets.
- Ignoring crypto frictions like transfer time and KYC checks that can make you miss the best line.
Tracking: the habit that compounds edges
Log every bet: date/time, sportsbook, market, odds, your fair price, no-vig estimate, CLV versus close, stake, result. Over a statistically meaningful sample, positive CLV plus disciplined staking is what usually separates signal from noise.
Quick reference formulas
- Implied probability (American odds): +A → 100/(A+100); −A → A/(A+100) using absolute A.
- Overround (two-way or multi-way): sum of all implied probabilities − 100%.
- No-vig probability: each implied probability ÷ sum of all implied probabilities.
Responsible betting and legality
Only bet with licensed operators in your jurisdiction, set hard limits, and take breaks. If you’re in a regulated market, expect source-of-funds checks for crypto. If gambling stops being fun, seek help from responsible-gambling services where you live.
FAQs
What is Closing Line Value (CLV) and why does it matter?
CLV measures whether your average odds beat the market’s final price before the event starts. Persistent positive CLV is widely used as evidence of a good betting process.
How do I know if a bet is truly +EV?
Convert odds to implied probabilities, remove the vig to get fair odds, and compare with your own assessed probabilities. If your probability is higher, the bet is +EV — then stake proportionally.
Are stablecoins better for bankrolls?
Stablecoins can reduce price volatility versus BTC/ETH, but they carry issuer and peg risks. Understand those trade-offs before choosing how to denominate your bankroll.
