First The playbook
Everything we believe about sports betting, reduced to rules you can actually follow, with the sources we learned them from.
House rules
If you only read one part of this site, read this.
- Decide what you can lose. That is the bankroll.
Pick an amount whose total loss would not change your life. Move it into one betting account. Never add to it. Walters tells new bettors to assume they will lose everything they start with and to size accordingly.
- Size every bet off the bankroll, not off your mood.
One unit is 1% of bankroll. Our standard play is 5 units and a rare press play is 7.5 units. Walters' rule is 1 to 3 units. Both are flat-betting systems: the size is set before the week starts, not after a win or a loss. Use the Tools page to set yours.
- No parlays. No teasers. No same-game stacks.
Each leg carries its own vig and the book compounds it. If you cannot beat the number straight, you will not beat it in a parlay. You will just lose faster.
- Know the break-even number.
At -110 it is 52.38%. At -120 it is 54.5%. Anyone claiming a long-run 60% win rate on sides is either lying or about to regress. The pros who beat the game live in the mid 50s.
- Shop the line. Always.
Half a point and five cents of price, bet after bet, is the difference between a winner and a loser over a season. Miller and Davidow show how multiple books let you build a better price than any single book offers. Have accounts at more than one.
- If the number is gone, the bet is gone.
You liked a team at -3. It is now -4.5. That is a different bet. Pass. Adapting means finding the next good spot, not forcing the one you already fell in love with.
- Bet what the market is missing, not what you noticed on TV.
Miller and Davidow's test for a real angle: predictable, quantifiable and not already in the line. Injuries everyone knows about are in the line. A starting pitcher's last outing is in the line.
- Track every bet and grade the decision, not the result.
Log the date, the side, the price, the size and why. Review monthly. A good bet that lost is still a good bet. Duke calls grading on outcomes "resulting," and it is how bettors talk themselves into bad habits.
- Never chase. Never press a loss.
The size of your next bet has nothing to do with the result of your last one. Set a daily and weekly stop rule before you place a bet and keep it.
- Say "I'm not sure" out loud.
Confidence is not an edge. Duke's whole book is about getting comfortable with uncertainty so you can make the best decision available instead of the one that feels best.
Four habits worth stealing
None of these athletes have anything to do with this site. Their habits have everything to do with betting well.
12 Discipline
The most decorated quarterback ever was never the most gifted. He was the most consistent. Same preparation, same diet, same film routine, for two decades. The betting translation is boring on purpose: same bet size, same line shopping, same log entry, every single play. The edge is in the repetition.
23 Process
Cut from his high school varsity team, then famous for practicing harder than anyone in the gym. He trusted that preparation produced results, not the reverse. In betting, your process is the only thing you control. The result of a single game is noise. Build the process, then let the sample size do the talking.
15 Adapt
The best improviser the position has seen. When the called play dies, he does not force it; he finds the next option. Lines move. Injuries drop. Weather changes. When the spot you liked disappears, do not force it. Find the next good number or pass.
24 / 8 Obsession
Famous for 4 a.m. workouts and for studying his own film more than anyone else's. That is the tracking habit. Most bettors remember their wins and forget their losses. Obsessive bettors log everything and study the losses harder, because that is where the leaks are.
The three books behind this site
Buy them, read them, then read them again after your first losing month. What follows are the ideas we lean on most, with links to the sources we drew from.
Thinking in Bets
Annie Duke, 2018. A former professional poker player on making decisions when you do not have all the facts. Not a betting book. The best betting book on this list.
- Resulting. Judging a decision by its outcome. A great bet that loses is still a great bet; a reckless bet that wins is still reckless. Grade the decision.
- Life is poker, not chess. Chess has no hidden information and no luck. Sports do. Expect to lose good bets and win bad ones, and do not let either change your process.
- "I'm not sure." Put a percentage on your beliefs instead of treating them as certain. A bettor who says "65% on this side" learns faster than one who says "lock."
- Pre-mortems and kill criteria. Before the season, imagine it went badly and write down why. Set the conditions under which you stop or resize before you are in a hole.
- Ulysses contracts. Precommit. The daily loss limit and the fixed unit size are Ulysses contracts: you tie yourself to the mast while you are still calm.
- A truth-seeking group. Find people who will tell you a bet was bad even when it cashed.
Sources: annieduke.com, Durmonski summary, Sumizeit summary.
The Logic of Sports Betting
Ed Miller and Matthew Davidow, 2019. How sportsbooks actually set and move prices, and what that means for someone trying to beat them.
- Think like the book. Books are not trying to balance action so much as price the market well and move with sharp money. Understanding why a line moves is worth more than any power rating.
- Synthetic hold. With accounts at several books you can often find the best side at one and the best price at another, creating a better market than any one book offers. Line shopping is not optional.
- What a real edge looks like. An angle has to be predictable, quantifiable and not already in the line. If a casual fan knows it, the line already knows it.
- Break-even math. Convert every price to a break-even percentage and compare it to your honest estimate. If there is no gap, there is no bet.
- Parlays. If your individual bets lose money, parlaying them loses money faster. Parlays only make sense with real, correlated edges, which almost nobody has.
Sources: Las Vegas Review-Journal, Pinnacle review.
Gambler: Secrets from a Life at Risk
Billy Walters, 2023. The most successful sports bettor on record on how he did it, including the money management chapters most readers skip.
- Assume you will lose it all. Start with a bankroll you can afford to lose entirely, and never bet money you need.
- 1 to 3% per bet. Walters defines one unit as 1% of bankroll and caps even his strongest plays at 3 units. He uses half units for marginal spots. Our 5 unit standard is more aggressive than this, and we say so on the Tools page.
- Flat betting. Size does not change after a win or a loss. The only thing that changes it is a recalculated bankroll.
- 52.38%. The break-even number at -110. He treats sustained 55 to 57% as elite.
- Sucker bets. Parlays, teasers and most props. The books push them because the hold is enormous.
- Shop lines and bet early or late. Have multiple outs, know when your market is most mispriced, and record everything.
Sources: ESPN excerpt, Covers, Shortform summary, Doc's Sports review, Yahoo Sports.
Blackjack, the version you can remember
Not a sports bet, but the same idea: play the math, not the feeling. Basic strategy cuts the house edge to about half a percent. It does not beat the game, so the bankroll rules still apply: a session stake you can lose, flat bets, no side bets, no chasing.
Five lines to memorize
- 17 or more, stand. 8 or less, hit. 11, double. The easy ends of the chart.
- Dealer 2 to 6 is weak. Let them bust. Stand on hard 13 to 16. Stand on 12 against 4, 5 and 6 only.
- Dealer 7 to Ace is strong. Hit to 17. No standing on 12 to 16. Surrender 16 against 9, 10 or Ace and 15 against a 10 if the table allows it.
- Aces and 8s, always split. 10s and 5s, never. 5s are a hard 10, so double them against 2 to 9.
- Never take insurance. Never play a 6:5 table. Blackjack should pay 3:2. If the felt says 6:5, walk.
Splitting
Memory hook: pairs want to split against a weak dealer, and the stronger your pair, the fewer dealer cards it splits against.
| Pair | Split when dealer shows |
|---|---|
| A, A and 8, 8 | Always |
| 9, 9 | 2 to 9, except 7 |
| 7, 7 | 2 to 7 |
| 6, 6 | 2 to 6 |
| 4, 4 | 5 and 6 only |
| 2, 2 and 3, 3 | 2 to 7 |
| 10, 10 and 5, 5 | Never |
Soft hands (Ace counts as 11)
Memory hook: the doubling window opens one dealer card wider each step up from A,2. Start at 5 and 6, then 4 to 6, then 3 to 6, then 2 to 6. Otherwise hit, except soft 18 and up.
| Hand | Double against | Otherwise |
|---|---|---|
| A,2 and A,3 | 5, 6 | Hit |
| A,4 and A,5 | 4 to 6 | Hit |
| A,6 | 3 to 6 | Hit |
| A,7 | 2 to 6 | Stand on 7 or 8, hit on 9 to A |
| A,8 | 6 only | Stand |
| A,9 and A,10 | Never | Stand |
If the table will not let you double, hit, except soft 18 against 2 to 6, which stands.
Hard totals
Memory hook: the double window for 9, 10 and 11 widens as the total goes up. 9 against 3 to 6, 10 against 2 to 9, 11 against everything.
| Hand | Play |
|---|---|
| 17 and up | Stand |
| 13 to 16 | Stand on 2 to 6, hit on 7 to A |
| 12 | Stand on 4 to 6, hit everything else |
| 11 | Double |
| 10 | Double on 2 to 9, hit on 10, A |
| 9 | Double on 3 to 6, otherwise hit |
| 8 and below | Hit |
| Surrender | 16 on 9, 10, A. 15 on 10 |
Assumes a standard multi-deck game with doubling after a split allowed. Table rules vary, and some rooms do not offer surrender. Even played perfectly, blackjack has a house edge; treat it as entertainment with a price, never as a way to win back a sports loss.
Now size the bankroll
Reading is cheap. The habit that actually protects you is picking a number you can lose and sizing every bet off it.
Open the tools