<P> In baseball, batting average (AVG) is a measure of a batter's success rate in achieving a hit during an at bat, and is calculated by dividing a player's hits by his at bats . The achievement of a . 400 batting average in a season is recognized as "the standard of hitting excellence", in light of how batting . 300 in a season is already regarded as solid . Twenty players have recorded a batting average of at least . 400 in a single Major League Baseball (MLB) season as of 2017, the last being Ted Williams of the Boston Red Sox in 1941 . Three players--Ed Delahanty, Ty Cobb and Rogers Hornsby--have accomplished the feat in three different seasons, and no player has ever hit over . 440, a single - season record established by Hugh Duffy in 1894 . Ross Barnes was the first player to bat . 400 in a season, posting a . 429 batting average in the National League's inaugural 1876 season . </P> <P> In total, 20 players have reached the . 400 mark in MLB history and five have done so more than once . Of these, ten were right - handed batters, nine were left - handed, and one was a switch hitter, meaning he could bat from either side of the plate . Two of these players (Terry and Williams) played for only one major league team . The Philadelphia Phillies are the only franchise to have four players reach the milestone while on their roster: Delahanty, Billy Hamilton, Sam Thompson, and Tuck Turner, all of whom attained a batting average over . 400 during the 1894 season . Three players won the Most Valuable Player (MVP) Award in the same year as their . 400 season . Tip O'Neill, Nap Lajoie, and Hornsby are the only players to have earned the Triple Crown alongside achieving a . 400 batting average, leading their respective leagues in batting average, home runs and runs batted in (RBI). Although Shoeless Joe Jackson's . 408 batting average in 1911 did not earn him the American League's batting title, it established a major league record for a rookie that stands to this day . Fred Dunlap has the lowest career batting average among players who have batted . 400 in a season with . 292, while Cobb--with . 366--recorded the highest career average in major league history . </P>

Who has the highest single season batting average in mlb history