MLB Home Run Glossary

A simple explanation of the metrics shown on the Home Run Model table.

• L5 / L10: How many of the player’s last 5 or 10 games included a home run.
• HH%: How often the hitter’s batted balls are hit at least 95 mph.
• Barrel%: How often the hitter produces the ideal combination of exit velocity and launch angle.
• EV: The hitter’s average exit velocity, measured in mph.
• xISO: Expected isolated power—an estimate of extra-base-hit power based on quality of contact.
• ISO vs Hand: The hitter’s isolated power against pitchers with the same handedness as today’s starter.
• Pitcher HH%: How often the pitcher allows batted balls hit at least 95 mph.
• Pitcher Barrel%: How often the pitcher allows barrel-quality contact.
• Pitcher xISO: The expected extra-base-hit power the pitcher allows based on contact quality.
• HR/9: Home runs allowed by the pitcher per nine innings.
• Best Book: The strongest currently listed sportsbook price for that player to hit a home run.
• Model Odds: TDE’s home-run probability converted into fair American odds.