From Yaz's Baseball Reference page:
Carl Yastrzemski was a Hall of Fame outfielder who played his entire career with the Boston Red Sox. An eighteen time All-Star, Yastrzemski is the last man to win a Triple Crown in Major League Baseball.
Yaz had one of the longest careers in major league history, appearing in 3308 games over twenty-three seasons. He shares the record for most years with the same team, tied with career Baltimore Oriole Brooks Robinson. He is second on the all-time list for games played, and third in at-bats. A top hitter who led the American League in numerous categories, including batting average three times and on-base percentage five times, he was also am excellent fielder, winning seven Gold Gloves. In two World Series appearances he hit a robust .352.
He won the 1967 American League Triple Crown; not only that, he was at his best down the stretch, when he carried the Red Sox to a miracle pennant in an epic four-team race that was not decided until the season's last day. He won the league's MVP Award that year. He is the last batter to win a Triple Crown, a feat that has since become much more difficult due to the greater number of regular players in each league as a result of expansion. However, many fans remember him just as much for leading the American League in 1968 with a .301 batting average. It was the bottom of the second dead-ball era, and he was the only player in the league who hit .300.
Originally a left-fielder - he replaced the great Ted Williams at the position when Williams retired after the 1960 season -, he was known for his ability to play Fenway Park's Green Monster and cut off opposite baserunners on the basepaths. He player more often at first base and DH in the latter part of his career. He had a highly distinctive batting stance that had him holding the bat vertically above shoulder height as the pitcher began his wind-up; it is jokingly said that he ruined thousands of New England boys' hitting prospects as they tried to imitate their hero's highly-unorthodox stance. It worked for him, though: he holds the record for most career hits without ever collecting 200 hits in a single season.