A statistic in baseball created by Bill James which combines a players home run and stolen base production into a single number.
It is calculated as follows:
(2 x Home Runs x Stolen Bases) / (Home Runs + Stolen Bases)
Bill James created this statistic with the goal of quantifying the various home-run/stolen bases clubs often quoted in baseball such as the 30/30 and 40/40 clubs. The highest single-season Power-speed Number recorded was by Alex Rodriguez during the 1998 season when he put up a 43.9 PSN.