Every bet is a claim that the price is wrong. Results are a slow way to check that claim: good bets lose all the time and bad ones win. The closing line is a fast one. Play by play, it tells you whether the market came around to your number after you took it.
What the closing line is
The closing line is the last price on a side before the game starts: at kickoff, first pitch, tip-off or puck drop. Once the game is under way, live betting is a different market with different information.
Between open and close, lines move as information and money arrive: injury reports, confirmed lineups, starting pitchers and goalies, weather, and bets from accounts the books respect. Each move is the market correcting itself. By the close it has seen everything it is going to see before the game, and made every correction it is going to make.
Closing line value
Closing line value (CLV) is the gap between the price you took and the closing price on the same side. Draft a side at −130 and watch it close at −142: you got a better number than the market's final estimate. That is beating the close. If it closes at −120 instead, the market moved away from you and you paid more than the closing price.
CLV does not care who won. It asks one question: once the market had the most information it would ever have before the game, was your price still a good one?
Why the close is the benchmark
A sharp book's closing price, with the margin removed, is widely treated as the best public estimate of a game's true probabilities. Sharp books like Pinnacle raise their limits as the start approaches, so much of the biggest and best-informed money arrives late, and each respected bet that moves the line pushes it toward fair. It is the same reason Guru-frat grades every play against Pinnacle's no-vig price (see why Pinnacle is the reference).
If you keep getting a better number than that estimate, you keep getting ahead of the information and money that set it. Luck rarely does that play after play, and it shows up on every play, win or lose. Results take far longer to say anything:
After 100 bets, a winning record and a losing one are both well inside the range of luck. It takes around 9,100 bets before a true 2% edge sits two standard errors clear of zero. CLV is known for every play as soon as the market closes, and one price comparison does not swing the way one win or loss does. Recreational books watch it too: accounts that keep beating the close are often limited long before their results prove anything.
How Guru-frat measures it
In cents
American odds have a hole in the middle: no price exists between −100 and +100. Guru-frat closes it with a linear cents scale on which +100 and −100 are the same point, zero. On that scale −130 is −30, +105 is +5, and a move from +105 to −105 is 10 cents, not 210.
Positive means you beat the close; negative means the market closed at a better price than yours. The rule is the same for favorites and underdogs: +150 against a close of +138 is 50 − 38 = +12¢. Guru-frat measures cents against the close at the book where you drafted.
In probability
Cents are quick to read, but a cent is not a fixed amount of probability. Convert both prices to implied probability (one over decimal odds) and the difference tells you how far the market moved toward your side, whatever odds format you think in. Swap the closing price for Pinnacle's no-vig closing probability and you get CLV as a percentage: the EV formula behind the grades, evaluated at the close instead of the moment you drafted.
| Drafted → close | CLV | Implied probability | Change (pts) |
|---|---|---|---|
| −105 → −115 | +10¢ | 51.2% → 53.5% | +2.27 |
| +105 → −105 | +10¢ | 48.8% → 51.2% | +2.44 |
| −130 → −142 | +12¢ | 56.5% → 58.7% | +2.16 |
| +150 → +138 | +12¢ | 40.0% → 42.0% | +2.02 |
| −250 → −270 | +20¢ | 71.4% → 73.0% | +1.54 |
| +300 → +280 | +20¢ | 25.0% → 26.3% | +1.32 |
Near even money, 10¢ is worth more than two points of probability. Out at −250 or +300, twice as many cents buy only 1.3 to 1.5 points. When you compare CLV across plays, compare like with like, or use the probability view.
Worked example from today's board
You drafted Panthers −1.5 at FanDuel at +257. The same side there is now +245: +12¢ in your favor, or +0.97 pts of implied probability. Against Pinnacle's no-vig price of +232, your number carries +7.5% EV, while a player drafting the same side now gets +3.9%, graded B on today's board.
The puck drop hasn't happened yet, so this is CLV against the line now; it becomes final at the close. If Pinnacle's fair price is still +232 then, +7.5% is this play's CLV as a percentage. Open it in Game Center to see how every book and the fair line have moved.
Season 1 preseason: board prices are illustrative and update with the board.
Drafting starts the clock
Guru-frat is not a sportsbook. You place bets at your own book; what Guru-frat tracks is your draft. Draft a graded play from Play-by-Play, Game Center or your Locker Room, and Guru-frat records the selection, the book and the price at that moment. CLV tracking starts there.
- Your Locker Room lists your drafted plays as your price against the line now, +257 → +245, with the CLV in cents.
- When the game starts, the last pre-game price becomes the close and that play's CLV is final.
- Your Player Card rolls it up for the season: average CLV and the share of drafted plays that beat the close.
Draft when you place the bet. If your book moves between the two, the CLV on your card is not the CLV you actually got.
+50 XP for beating the close
A drafted play that beats the close earns +50 XP, more than drafting it did (+20 for a B or better). Whether the play wins makes no difference. A losing play that beat the close earns the full +50; a winning play that closed worse than you drafted it earns nothing for CLV.
Beating the close comes from decisions you control: taking a price before the market corrects it, shopping every book for the best number, and passing when the value is gone. Season standings are ranked by XP with ties broken by CLV, and beating the close ten times unlocks the Closer trophy.
What CLV can't tell you
- Small samples. CLV settles faster than results, but ten plays is still ten plays. Judge it over a season of drafts, not a weekend.
- Variance in the move itself. Lines move on news you could not have known. If a starter is ruled out an hour after you draft, you beat the close by luck. Over many plays that washes out; on one play it does not. And positive CLV is never a promise: plays that beat the close still lose, often.
- Compare against a sharp close. A recreational book's close still carries its margin, and it can lag the sharp market or be shaded toward the side its customers like. Draft −120 and see your book close at −125, and you are +5¢. But if Pinnacle's no-vig price closed at −118 (54.1%), you still took a worse number than fair: −0.8% EV at the close. Game Center plots the fair line next to every book so you can check.
- Deep markets only. The close is only as good as the market behind it. Moneylines, spreads and totals in major leagues are deep; in thin markets a closing price carries much less information.
Keep going
Ready to track your own? Draft plays from Play-by-Play or Game Center, and see what each league unlocks on Pricing.