In the year of his 500th home run...

Earlier this season Albert Pujols became the 26th player in MLB history to hit his 500th career home run. Pujols' first two seasons with the Angels did not go especially well, as his offensive numbers were down in almost every category, and while a decline was to be expected, in 2013 that decline felt especially steep. I wondered if his time as a great player had come to an abrupt end. In 2014 though, Pujols' production has rebounded, not to the level of his incredible peak from 2003 to 2010, when he was one of the half dozen best players in baseball every season (those days are over), but to where he was in 2011 and 2012. His strong start had me wondering how each member of the 500-HR club did in the season in which they reached that level, so I set out to investigate.

Here are the dates of each player's 500th career home run, in chronological order:

Babe Ruth (August 11, 1929)
Jimmie Foxx (September 24, 1940)

Mel Ott (August 1, 1945)

Ted Williams (June 17, 1960)

Willie Mays (September 13, 1965)

Mickey Mantle (May 14, 1967)

Eddie Mathews (July 14, 1967)

Hank Aaron (July 14, 1968)

Ernie Banks (May 12, 1970)

Harmon Killebrew (August 10, 1971)

Frank Robinson (September 13, 1971)

Willie McCovey (June 30, 1978)

Reggie Jackson (September 17, 1984)

Mike Schmidt (April 18, 1987)

Eddie Murray (September 6, 1996)

Mark McGwire (August 5, 1999)

Barry Bonds (April 17, 2001)

Sammy Sosa (April 4, 2003)

Rafael Palmeiro (May 11, 2003)

Ken Griffey (June 20, 2004)

Frank Thomas (June 28, 2007)
Alex Rodriguez (August 4, 2007)

Jim Thome (September 16, 2007)

Manny Ramirez (May 31, 2008)

Gary Sheffield (April 17, 2009)

Albert Pujols (April 22, 2014)

As you can see, it was a while before Ruth had any company, and members joined the club very rarely for a few decades. Then, in the late 60s and early 70s, the club's size more than doubled. Things slowed down again until the late 90s, when players began to reach 500 regularly, an average of almost one a season. Pujols was the first new member in 5 years though, the longest gap since that between Schmidt and Murray more than two decades earlier.

Mantle and Mathews entered two months apart in 1967, Killebrew and Robinson joined only 34 days apart in 1971, a span just shorter than the 37 days between Sosa and Palmeiro in 2003. Thomas, Rodriguez, and Thome in 2007 are the only trio to join the club in the same season, and I doubt we'll see that happen again any time soon.

Here is each player again, with their player-age for the season in which they hit #500, along with the total number of home runs they hit that year, how many plate appearances they had, and their OPS+:

Player	Age	PA	HR	OPS+
Babe Ruth	34	587	46	193
Jimmie Foxx	32	618	36	150
Mel Ott	36	534	21	151
Ted Williams	41	390	29	190
Willie Mays	34	638	52	185
Mickey Mantle	35	553	22	149
Eddie Mathews	35	511	16	111
Hank Aaron	34	676	29	153
Ernie Banks	39	247	12	96
Harmon Killebrew	35	624	28	138
Frank Robinson	35	545	28	153
Willie McCovey	40	390	12	97
Reggie Jackson	38	584	25	95
Mike Schmidt	37	613	35	142
Eddie Murray	40	637	22	87
Mark McGwire	35	661	65	176
Barry Bonds	36	664	73	259
Sammy Sosa	34	589	40	133
Rafael Palmeiro	38	654	38	117
Ken Griffey	34	348	20	123
Frank Thomas	39	624	26	125
Alex Rodriguez	31	708	54	176
Jim Thome	36	536	35	150
Manny Ramirez	36	654	37	166
Gary Sheffield	40	312	10	119
Albert Pujols**	34	235	14	134

 *Pujols' numbers are through May 30

Half the 26 players were in their age-36 season or older at the time of their 500th home run, half were in their age-35 season or younger. That means Pujols is among the younger players to reach 500, with only Rodriguez (31) and Foxx (32) doing it in a younger season.

20 of the previous 25 guys to reach 500 had 500+ plate appearances that season, while only Ernie Banks had fewer than 300.

Top HR totals for 500th-HR season:

1) Barry Bonds - 73

2) Mark McGwire - 65

3) Alex Rodriguez - 54

4) Willie Mays - 52

5) Babe Ruth - 46

Pujols is on pace for 42, which would put him 6th on that list. The median number of home runs in the previous 25 seasons is 29. I'm sort of surprised at how strong these seasons were, given that most of them happened when the players were at an age that would be considered past their prime. I guess it's a reminder that guys who hit so many home runs are a different sort than the typical MLB player. Heck, while Pujols is on pace to reach one of the highest home run totals of these guys, his current 134 OPS+, good as it is, would place him in the bottom half among these 26.