A horse

When my dad took me to Fenway for the first time(a doubleheader vs. the new Los Angeles Angels), Yaz was the rookie from Long Island replacing Ted Williams in left field.He won everyone over and in 1967, had a season like no other. He always got a hit when needed and played the wall (commercially known as the Green Monster)perfectly. From that point on, the Red Sox stopped being a doormat and become a contender every season. Yaz was the difference. By the way, you spelled his name wrong.

If Williams is the greatest left-fielder in team history, which I think he is, its not by a huge margin over this guy.

Williams was the better hitter by a good way, but Yaz was infinitely superior in the field, and was no slouch at the plate.

Had a monstrous year in 1967, particularly in September when he may have had the best single month of any hitter in history, and almost singlehandedly willed the Sox to the pennant.

The best of the great left fielders the team had defensively speaking. Of all of the team's very  biggest names that are primarily associated with them,, he probably had the oddest career pattern- in a nutshell, he went from legend (Williams) replacer to underachieving guy  to batting champion to superstar to having a strange early to mid 70's slump to being productive again in the mid to late 70's to being the sort of old timer who almost  doesn't really appear anymore- the kind that gets to decide when its time to quit, even though he's hurting the team to some degree.

The numbers dont lie, Yaz was the Man in a age of great pitching.