Replay · NFL
Test a rule against real closing prices.
Each rule here was replayed against every settled line it would have bet, at the closing price, with how sure the result is. Choose one to read it.
00Build a rule
Six groups, the common choice open and the rest one click away. Every control is a field the engine takes; nothing on this page runs a rule.
01Rules
4 rules replayed · 4 more listed that the engine cannot run · Film Room
- Loses01Fade every over13,680 bets · −3.3% ROI · open in the builder
- Unclear02Rush attempts unders2,256 bets · −1.8% ROI · open in the builder
- Loses03Chase the streak1,150 bets · −13.2% ROI · open in the builder
- Cannot run04Follow the model's leansWaiting for walk-forward model predictions persisted for the historical seasons.
- Cannot run05Buy the middleWaiting for a rule language with two legs: lab.strategy/1 bets one side at one price.
- Cannot run06Arbitrage between booksWaiting for a rule language with two legs: lab.strategy/1 bets one side at one price.
- Loses07Home underdogs of 3 to 71,400 bets · −5.6% ROI · open in the builder
- Cannot run08Unders in the windWaiting for forecast weather joined to the replayed games.
4 rules replayed on this site so far. The more rules are tried, the more likely one clears zero by chance alone: with 4 tried, a 95% interval that allows for it spans about ±2.50 standard errors (Bonferroni), not ±1.96. The intervals on this page are the plain 95%.
Buy the middle
Listed · not replayed
Waiting for a rule language with two legs: lab.strategy/1 bets one side at one price.
The engine cannot run this rule, and says why:
- not expressible in lab.strategy/1: a middle is TWO legs at two books at two thresholds; lab.strategy/1 is a single-leg language (one side, one price source), and the register figure is taken over every fresh pre-kickoff snapshot of the raw archive, where the universe holds one close per claim. No strategy in this schema expresses it, so no run of this engine can reproduce it - the library card must cite the R16 script, or the schema must grow a
legsfield (a lab.strategy/2).
Measured elsewhere: R16 / brief 023 Part 2, research/bookvbook.py: spreads middle mean EV -2.54pp empirical, -2.65pp realized, n=10,860 over 848 games (data/repairs/bookvbook-2026-09-17.txt).
Film Room lists every rule, replayed or not.
Hypothetical results · nothing here was bet · not advice · lab index written Sun, Sep 27, 2:14 AM ET