MLB NRFI / YRFI Explorer
BetaNRFI = No Run First Inning. YRFI = Yes Run First Inning. First-inning ERA, lineup first-inning scoring rates, park factors, and historical hit rates — assembled for every game on tonight\u2019s slate.
Tonight\u2019s NRFI board — sorted by edge
| Matchup | Starters 1st-Inn ERA | Lineup 1st-Inn RS/G | Park NRFI% | NRFI Odds | Implied / Model | Edge | Pick |
|---|---|---|---|---|---|---|---|
BOS @ TB 7:05 PM ET • Tropicana Field Garrett Crochet vs Shane Baz | 1.89 / 2.14 season 2.94 / 3.52 | 0.72 / 0.51 season 4.8 / 3.9 | 62% | +105 YRFI -128 5 books | 48.8% 60.5% | +11.7% | NRFI |
NYY @ BAL 7:05 PM ET • Oriole Park at Camden Yards Gerrit Cole vs Grayson Rodriguez | 2.45 / 5.67 season 3.14 / 4.22 | 0.98 / 0.81 season 5.4 / 4.9 | 54% | -115 YRFI -105 6 books | 53.5% 41.8% | -11.7% | YRFI |
LAD @ SD 9:40 PM ET • Petco Park Clayton Kershaw vs Yu Darvish | 1.98 / 2.44 season 2.88 / 3.41 | 0.88 / 0.61 season 5.1 / 4.4 | 67% | -130 YRFI +110 7 books | 56.5% 67.0% | +10.5% | NRFI |
CHC @ MIL 8:10 PM ET • American Family Field Shota Imanaga vs Freddy Peralta | 2.02 / 2.18 season 3.05 / 3.29 | 0.64 / 0.58 season 4.3 / 4.1 | 63% | -120 YRFI +100 6 books | 54.5% 62.8% | +8.3% | NRFI |
PHI @ WAS 7:05 PM ET • Nationals Park Zack Wheeler vs MacKenzie Gore | 2.21 / 4.85 season 2.95 / 4.02 | 0.85 / 0.59 season 4.8 / 3.8 | 56% | +102 YRFI -122 5 books | 49.5% 44.8% | -4.7% | YRFI |
HOU @ TEX 8:05 PM ET • Globe Life Field Framber Valdez vs Nathan Eovaldi | 3.15 / 4.12 season 3.22 / 3.78 | 0.78 / 0.74 season 4.7 / 4.5 | 51% | -108 YRFI -112 5 books | 51.9% 53.4% | +1.5% | PASS |
What is NRFI/YRFI and why does it matter?
NRFI (No Run First Inning) is a bet that neither team scores in the top or bottom of the first inning. YRFI (Yes Run First Inning) is the inverse — at least one run scores in the first.
It\u2019s one of the fastest-growing bet types in MLB because the first inning is a self-contained event with relatively clean inputs: the two starting pitchers, the top of each lineup, and the ballpark. Bullpen decisions and late-game randomness don\u2019t apply.
The main edge for NRFI bettors comes from three inputs the market consistently misprices:
- First-inning ERA vs season ERA: pitchers often perform very differently in the first inning vs the rest of the game. A pitcher with a 4.20 season ERA but a 1.98 first-inning ERA (slow starter in reverse) is routinely undervalued on NRFI.
- Lineup first-inning scoring rate: top-of-order production matters more than overall team runs/game. A lineup averaging 0.5 first-inning runs is a very different NRFI profile than one averaging 0.9.
- Park first-inning rate: some parks consistently suppress early scoring (pitcher-friendly lighting, marine-layer conditions, deep foul territory) and the market doesn\u2019t always price this in.
When a book posts NRFI at −115 (implying 53.5%) but the real probability is closer to 62%, that\u2019s a +8.5% edge. Find 2–3 of those per week and it compounds.