PowerâÂÂspeed number or power/speed number (PSN) is a sabermetrics baseball statistic developed by baseball author and analyst Bill James which combines a player's home run and stolen base numbers into one number.
The formula is:
It is the harmonic mean of the two totals.
James introduced the powerâÂÂspeed number in his commentary on Bobby Bonds, writing "it is so crafted that a player who does well in both home runs and stolen bases will rate high, and his rating is determined by the balance of the two as well as by the total."
The highest single-season powerâÂÂspeed number was recorded by Shohei Ohtani of the Los Angeles Dodgers in 2024, with 54 home runs and 59 stolen bases for a power-speed number of 56.39. It was previously held by Ronald Acuña Jr. who hit 41 home runs and stole 73 bases in 2023 to record a powerâÂÂspeed number of 52.51.
The highest career powerâÂÂspeed number belongs to Barry Bonds. Bonds had 762 career home runs and 514 career stolen bases for a career powerâÂÂspeed number of 613.9. Rickey Henderson is second on the career list at 490.4, followed by Willie Mays (447.1), Alex Rodriguez (446.8), Barry's father Bobby Bonds (386.0), and Joe Morgan (385.9).
The highest active career powerâÂÂspeed numbers belong to Jose Altuve (285.78), José RamÃÂrez (284.5), and Mike Trout (279.55), .