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The stats behind the props.

A plain-English reference for the metrics BallBet uses to research MLB props — what each one measures, why it matters, and where to see it on the site. Every projection on BallBet is built from these inputs; the methodology explains how they come together.

BallBet metric
HR DNA →
BallBet's per-batter home-run signature: how much a hitter's home-run rate rises or falls under specific, pre-defined conditions.

BallBet metrics

HR DNA
BallBet's per-batter home-run signature: how much a hitter's home-run rate rises or falls under specific, pre-defined conditions.

Contact quality

Exit velocity
The speed of the baseball off the bat, in miles per hour, measured at contact.
Launch angle
The vertical angle, in degrees, at which the ball leaves the bat after contact.
Barrel rate
The share of a hitter's batted balls that are 'barrels' — the exit-velocity and launch-angle combinations that historically produce elite results.
Hard-hit rate
The percentage of a hitter's batted balls struck at 95 mph or harder.
Expected wOBA (xwOBA)
An estimate of a hitter's weighted on-base average based on the quality of contact, stripping out the luck in where balls landed.
wOBA
A rate stat that weights each offensive outcome by its real run value, scaled to look like on-base percentage.

Power

Isolated power (ISO)
Slugging percentage minus batting average — a measure of a hitter's raw extra-base power.
HR per fly ball
The share of a hitter's fly balls that become home runs — or, for a pitcher, the share allowed.
Pull-air rate
The share of a hitter's batted balls hit in the air to their pull side — the most home-run-friendly contact a hitter can make.

Plate discipline

Strikeout rate (K%)
Strikeouts as a percentage of plate appearances — for hitters, a contact-frequency measure; for pitchers, a swing-and-miss measure.
Whiff rate
The share of swings that miss — a per-swing measure of bat-missing stuff or swing-and-miss tendency.
Platoon splits
The performance difference for a hitter or pitcher depending on the handedness of the opponent.

Environment

Park factor
An index of how much a ballpark inflates or suppresses a given outcome compared with a neutral park, where 100 is average.

Betting concepts

NRFI (No Runs First Inning)
A market on whether the first inning of a game is scoreless; NRFI is no runs, YRFI is yes runs.
First five innings (F5)
Markets settled on only the first five innings of a game, isolating the starting pitchers from the bullpens.
Closing line value (CLV)
The difference between the price you bet and the market's closing price — the single best long-run indicator that a betting process is sound.
Expected value (+EV)
The average result of a bet if it were repeated many times; a positive expected value means the price is better than the true probability implies.