slugging percentage

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A player's total number of bases reached on hits divided by official at bats, expressed as a three-digit decimal and used as a measure of batting power.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun baseball A statistic which compares the total number of bases achieved by a batter over that batter's number of at bats.