Tuesday marked 40th anniversary of Aaron's record-breaking home run

When it comes to great milestones in baseball history, this past week would be hard to beat.

Forty years ago on Tuesday, Alabama native Hank Aaron, who was playing for the Atlanta Braves, hit his 715th career home run in the fourth inning against the Los Angeles Dodgers in front of a crowd of 53,775 people at Atlanta-Fulton County Stadium. With the swing of his bat on that night in 1974, “Hammerin’ Hank” broke Babe Ruth’s long-standing record of 714 home runs. Aaron, who was inducted into the Baseball Hall of Fame in 1982, would go on to hit 755 career home runs.

One notable baseball anniversary that may have flown under the radar this week was the fact that 45 years ago on Monday, Los Angeles Dodgers’ pitcher Bill Singer recorded the first official save in Major League Baseball history. On April 7, 1969, Singer relieved Don Drysdale and pitched three shutout innings in a 3-2 win over the Cincinnati Reds at Crosley Field, which closed in 1970. Prior to the 1969 season, the save wasn’t an official MLB statistic even though the term had been used here and there as far back as 1952.

In baseball, the save statistic has a slippery definition. In a nutshell, a save is awarded to a relief pitcher who successfully maintains a lead through the end of the game.

This is only true though under certain conditions. For instance, the relief pitcher has to finish the game, and his team has to win. He also can’t be credited with the pitching win, and he has to pitch at least one-third of an inning.

To earn a save, the relief pitcher also has to meet one of the following conditions. He has to either pitch for at least three innings or he enters the game with the potential tying run either on base, at bat or on deck. Or he enters the game with a lead of no more than three runs and pitches for at least one inning.

As you can see, earning a save in baseball is no easy task. However, some relief pitchers have excelled at it over the years. Right-handed pitcher Mariano Rivera, who retired last year, is the all-time saves leader in MLB history with 652 saves to his credit. John Franco recorded 424 saves in his career, which is the most ever compiled by a left-handed pitcher.

Francisco Rodriguez collected 62 saves during the 2008 season while pitching for the Angels, which set the record for most saves in a single season. He broke the mark of 57 set in 1990 by Chicago White Sox right-hander Bobby Thigpen. The single season save record for lefties was set in 1993 by Chicago Cubs southpaw Randy Myers. The most saves Rivera has ever thrown in a single season was 53, which he pulled off in 2004.

When it comes to saves, one of the most impressive records ever set was the 84 consecutive saves Eric Gagne posted between 2002 and 2004 while pitching for the Dodgers. The next closest player on that list is Tom Gordon, who posted 54 straight saves for the Boston Red Sox between 1998 and 1999.