← Model Lab/Tier −1 — Disproven Theories/First Lead Comeback

First Lead Comeback

disprovenTier −1live

A popular live-betting theory tested against real MLB data. The strategy calls for betting the first-to-lead team when it falls behind before the 7th inning, at + money prices. Real data shows why this doesn't work.

📖 The Theory
  • Teams that score first to lead win 65.5% of games
  • When they fall behind, the market “overreacts” posting + money
  • Theorized win rate: 52–54% in these spots
  • Implied claim: ~+9% flat-bet ROI
📊 Real Data (2021)
  • 362 triggers in 2,422 games (14.9%)
  • Actual win rate: +26.0%
  • Breakeven at ~+153.9 odds: 39.4%
  • Flat-bet ROI: -36.4%
Why the theory fails: The 65.5% base rate reflects all games where the first-lead team establishes a lead — including the many where they never fall behind and coast to a win. Filtering to only the games where they lose the lead selects precisely the games where the opponent is outperforming. The market prices this correctly; the first-lead team wins only ~26% of those comeback attempts in 2021.
Games triggered
362
Trigger rate
14.9%
Win rate (triggered)
+26.0%
Flat-bet ROI
-36.4%

Win Rate by Inning of Lead Change

Every inning column shows how often the first-lead team won when the lead change happened in that inning. No inning shows a profitable rate vs. the market price.

InningTriggersFLC WinsWin RateAvg Est. OddsBreakevenEdge
Inning 2651827.7%+14740.5%-12.8%
Inning 3902022.2%+14840.3%-18.1%
Inning 4882730.7%+15639.1%-8.4%
Inning 5601423.3%+16138.3%-15.0%
Inning 6591525.4%+15938.6%-13.2%

Edge = Win Rate − Breakeven. Negative across all innings = no inning provides a profitable entry point.

Win Rate by Run Deficit at Trigger

Even the “best” scenario (down 1 run) fails to reach the break-even win rate needed to profit at typical live odds.

DeficitTriggersFLC WinsWin RateAvg Est. OddsBreakevenEdge
Down 1 run2067134.5%+14041.7%-7.2%
Down 2 runs881921.6%+15738.9%-17.3%
Down 3+ or more6845.9%+19234.2%-28.4%

5-Season Track Record (2021–2025)

The negative result is consistent — not a bad year or an anomaly.

SeasonWin RateFlat-Bet ROIvs. ~39% Breakeven
2025+26.2%-35.6%-13.3pp✗ unprofitable
2024+27.6%-31.8%-11.8pp✗ unprofitable
2023+26.4%-35.0%-13.0pp✗ unprofitable
2022+23.2%-42.5%-16.3pp✗ unprofitable
2021+26.0%-36.4%-13.4pp✗ unprofitable

pp = percentage points vs. ~39% break-even at avg +154 odds. Every season falls well short.

Bankroll Simulation

Starting from $100, betting every recommended trigger at the estimated live odds. All Kelly fractions and flat betting trend negative.

Game Log — All 2021 Triggers (362 games)

Every game where the first-lead team fell behind before the 7th inning. Filter by result to see patterns — or the lack thereof.

Data sourced from real MLB linescore game files (2,422 regular-season games in 2021). Odds are estimated using the formula: +{110 + (inning−1)×4 + deficit×18}, calibrated to typical live-betting lines. No live odds data feed was used; actual posted odds may differ. Win rates computed on all triggered games, not just recommended bets.