The most common type of first-inning bet is whether a run will be scored in the opening frame. Sportsbooks like DraftKings frequently offer promotional odds boosts for this type of market.

A wager on at least one run being scored in the first inning (Over 0.5 runs) is called a YRFI bet (Yes Run First Inning), while a wager on no runs being scored by either team (Under 0.5 runs) is called a NRFI bet (No Run First Inning).

With a YRFI bet, at least one team must score in the first inning for the bet to cash. This can be a good bet to target if one or both starting pitchers have high ERAs or if either lineup has a strong top of the batting order and has had success against the opposing pitcher.

Conversely, NRFIs require both teams to get through the first inning unscathed. It only takes one run to ruin a NRFI bet, which can happen on one swing if a pitcher makes a mistake.

Furthermore, teams usually stack their best hitters at the top of the lineup. The first three batters are guaranteed to bat for both teams in the first inning, making the pitcher’s job more difficult.

For NRFI bets, you’ll want to target matchups between two talented starting pitchers or games with two subpar offenses.

While looking at a pitcher’s overall stats is helpful, also make sure to review their first-inning stats like ERA, FIP and WHIP before placing a NRFI or YRFI wager. Some pitchers struggle in the first inning against more formidable hitters, but others pitch better at the start of the game when their arms are fresh.

Bottom line: Keep in mind that NRFIs and YRFIs are essentially coin flips. Through July 4, 2024, MLB games that season had an average of 0.48 runs in the first inning, indicating a slight lean toward NRFIs.