Who is generally considered the greatest baseball umpire of all time?

Tough to answer, because how do you define what makes an umpire "great"? There was an umpire named Bill Klem who worked about 100 years ago. He's kind of famous; there are a lot of old stories attributed to him, but famous is not the same as great. In the 1970s there was Ron Luciano--very colorful and flamboyant on the field. He wrote several books and made some TV appearances after he retired. Good umpire too, but great? IDK. Then there was Steve Palermo, who was shot and paralyzed in 1991 while trying to break up a robbery in progress. He was hailed as a hero for being a good samaritan, but few remember that he was also one of MLB's highest rated umpires at the time. Umpires have always been technically appraised by their employers, and player polls exist asking who they think the best umpires are or who their "favorite" umpires are, which are not always the same thing. Bottom line, the answer depends on a much more precise definition of what you think makes for a "great" umpire.

cody bellinger 

There are 10 umpires inducted in to the Hall of Fame. Of those, the one I respected the most was Nestor Chylak. He umped many a game that I watched in my youth.

I nominate the umpire that watched Freddie Merkle not quite get to 2nd base. 1908 Cubs vs Giants. The biggest bonehead play in the history of mlb