Intermediate Moneyline Strategy
If you're past the basics and want to bet more systematically, you need to start thinking in terms of expected value (EV), line movement, and how to actually quantify an edge.
Calculating Expected Value
Every bet has an expected value—the average amount you'd win or lose if you made that same bet thousands of times. The formula:
Where:
- = your estimated win probability
- profit = what you win if you're right
- stake = what you risk
Example: You bet $100 on the Suns at +150. You think they have a 45% chance to win.
- If they win: you profit $150
- If they lose: you lose $100
This bet has an expected value of +$12.50 per $100 wagered.
If you could make this exact bet 100 times, you'd expect to profit about $1,250 total.
The rule: Only bet when your EV is positive. If the line is +150 but you think the team only has a 35% chance to win, your EV is negative—don't bet.
Converting Odds to Implied Probability
You need to compare your probability estimate to the market's implied probability. Here's how to convert:
For negative odds (e.g., -180):
For positive odds (e.g., +150):
If you think the true probability is higher than the implied probability, you have an edge.
Sharp vs. Square Money
Not all money is equal. The market reacts differently to different types of bettors.
Square money comes from casual bettors. They tend to:
- Bet favorites (especially popular teams)
- Bet overs
- Bet on afternoon/night games more than early games
Sharp money comes from professional bettors and syndicates. They:
- Move lines quickly (books respect their action)
- Often bet underdogs
- Bet early before public money inflates the lines
If a line opens at -150 and moves to -155 with 80% of public bets on the favorite, that's square money. If a line opens at -150 and moves to -145 with 80% of public bets on the favorite, that's sharp money coming in on the dog—worth paying attention to.
Line Shopping Matters More Than You Think
Different sportsbooks offer different odds on the same game. This isn't negligible—it's the difference between winning and losing long-term.
Example: You want to bet $1,000 on the Lakers.
- Book A: Lakers -110 (risk $1,100 to win $1,000)
- Book B: Lakers -105 (risk $1,050 to win $1,000)
Book B saves you $50 in risk. Over 100 bets, that's $5,000 less risk for the same potential return.
If you're serious about betting, you need accounts at multiple books. Compare lines before every bet. Odds comparison tools exist—use them.
Finding Arbitrage Opportunities
Arbitrage is when you can bet both sides of a game at different books and guarantee a profit regardless of outcome. It's rare, but it exists.
Example:
- Book A: Celtics +105
- Book B: Hawks +105
One of these teams will win. If you bet $100 on each team, you risk $200 total and win $205 regardless of outcome. That's a $5 guaranteed profit (2.5% return).
In practice:
- Arbitrage windows are small (1-3%)
- They close fast
- Books don't like arb bettors (you might get limited)
- You need large bankroll to make it worthwhile
But if you're line shopping anyway and spot an arb, take it.
Closing Line Value (CLV)
One of the best predictors of long-term betting success is whether you beat the closing line.
The closing line is the final line right before the game starts. It's the sharpest line—the one that's absorbed the most information from the market.
If you consistently bet lines that move in your favor before close, you're likely finding +EV bets. If your bets consistently move against you, you're probably betting into the market rather than ahead of it.
Example:
- You bet Lakers -3.5 at noon
- Closing line: Lakers -5.5
- You gained 2 points of CLV (good)
Track this. If you're negative CLV over a large sample, something's wrong with your process.
Staking Methods
Flat betting is fine, but if you're calculating EV anyway, you might as well size your bets proportionally to your edge.
Fractional Kelly is the most common approach:
Where:
- = fraction of bankroll to bet
- = your win probability
- = decimal odds - 1
Most people use 25% or 50% of the full Kelly to reduce variance.
Example: You have a $10,000 bankroll. You think the Suns at +150 have a 45% chance to win.
Full Kelly says bet 8.3% ($830). Half Kelly says bet $415.
If your edge is smaller, Kelly tells you to bet less. If you have no edge, Kelly tells you not to bet at all.
Building a Tracking System
If you're not tracking your bets, you're flying blind. At minimum, track:
- Date/time of bet
- Team, line, odds
- Stake, potential profit
- Your estimated win probability
- Actual result
- Closing line
After a few hundred bets, you'll see patterns. Are you better at underdogs or favorites? Home or away teams? Early lines or late lines?
A simple spreadsheet works. Just be honest with yourself about what the data shows.