NFL Home Underdog ATS
Moderate home-underdog spread value
Rejected — 1,684 home-underdog bets returned PF 0.895, falling to PF 0.854 in the untouched 2020–2025 holdout. Home field plus 1.5–6.5 points did not overcome the spread price.
- Category
- Sports betting
- Window
- 1999-09-12 → 2026-01-04
- Instruments
- NFL regular-season point spreads
- Timeframe
- Pre-game closing spread
- Tested
- 2026-01-04
Measured equity history
Recorded directly from the chronological test ledger.
Shown in the backtest's native equity or cumulative P&L units. It is not scaled to an investment amount because the published artifact does not provide a defensible capital denominator.
How it works
BackfillingThe bet
What market behavior this strategy is wagering on.
Plain-English explainer is backfilling — check back tomorrow. We publish the explanation only once it's written and reviewed, never auto-filled.
How it decides
What makes it enter, size, and exit a position.
Plain-English explainer is backfilling — check back tomorrow. We publish the explanation only once it's written and reviewed, never auto-filled.
How it can break
The regimes and failure modes that turn the edge negative.
Plain-English explainer is backfilling — check back tomorrow. We publish the explanation only once it's written and reviewed, never auto-filled.
Gate scorecard — 2 / 6
auto-imported from results.json| # | Gate | Result | Pass |
|---|---|---|---|
| 01 | Minimum sample ≥250 bets | 1684 bets | ✓ |
| 02 | Profit factor ≥1.05 | PF 0.895 | ✗ |
| 03 | Max drawdown no worse than -20% | max DD -90.2% | ✗ |
| 04 | Real PF beats permutation p95 | real PF 0.895 vs permutation p95 0.896 | ✗ |
| 05 | Holdout profit factor ≥1.00 | holdout PF 0.854 | ✗ |
| 06 | Holdout sample ≥75 bets | 451 holdout bets | ✓ |
VERDICT: REJECTED
The broad “bet modest NFL home underdogs” rule did not survive costs or holdout testing. Across 1,684 regular-season bets from 1999–2025, betting home teams getting 1.5 to 6.5 points returned profit factor 0.895. The untouched 2020–2025 holdout was worse at 0.854.
The screen cleared only 2 of 6 sports-evidence gates. Its apparent folklore advantage was smaller than the standard spread price, and outcome permutations were not beaten. This is a clean negative result: home field plus underdog points was not enough.
The nflverse archive is suitable for a historical screen but does not identify a simultaneously executable named-book quote. That limitation cannot rescue a rule that was already negative at the consolidated close.
Frequently asked
Is NFL Home Underdog ATS profitable in 2026?
In this pre-registered backtest (1999-09-12 → 2026-01-04), NFL Home Underdog ATS returned a profit factor of 0.90 and passed 2/6 validation gates (placebo N/A). Verdict: REJECTED. Every result is published, pass or fail.
Has NFL Home Underdog ATS been backtested honestly?
Yes — through 6 pre-registered evidence gates appropriate to the available dataset, with the specification locked before any out-of-sample metric is computed. It failed and is published anyway.
Methodology: 11-gate validation — pre-registered spec, 6-gate battery, real market data. Full reproducible report: backtests/nfl_home_underdog/REPORT.md in the source repository.Author: Validated Research Team (Methodology v1.0 — 11-gate validation). Backtests are not investment advice.