MLB STAT is an acronym for Major League Baseball Statistics. The three letter abbreviations AVG, ERA, HRS, and RBI refer to four of the most commonly used statistics in baseball. AVG stands for batting average, which is the ratio of a player's hits to their at-bats. ERA stands for earned run average, which is the average number of earned runs a pitcher gives up per nine innings. HRS stands for home runs, which are hits that allow the batter to circle all the bases and score a run. RBI stands for runs batted in, which is the total number of runs a player has driven in with their at-bats.