On May 9, 2019, in Detroit, Albert Pujols slugged a solo home run to record his 2,000th career RBI. In doing so, he joined one of baseball's most exclusive fraternities.

Depending on which designation one refers to, Pujols became either the third or fifth member of the 2,000-RBI club. We know what you are thinking: "Third or fifth?" Allow us to explain.

Here¡¯s what¡¯s universally recognized: 2,000 RBIs is an incredibly difficult total to reach, and one that has eluded even the majority of inner-circle Hall of Fame hitters. According to the Elias Sports Bureau -- the official statistician of Major League Baseball -- there were just two members of the 2,000-RBI club before Pujols became the third.

All-time RBI leaders, per the Elias Sports Bureau?

1. Hank Aaron: 2,297
2. Albert Pujols: 2,218
3. Alex Rodriguez: 2,086
4. Barry Bonds: 1,996
5. Lou Gehrig: 1,994

But if one logs on to Baseball Reference and scrolls over to its career leaders section, the list looks a little different.

MLB¡¯s all-time RBI leaders, per Baseball-Reference

1. Hank Aaron: 2,297
2. Albert Pujols: 2,218
3. Babe Ruth: 2,214
4. Alex Rodriguez: 2,086
5. Cap Anson: 2,075

Either way you slice it, 2,000 RBIs is an incredibly rare milestone to reach. But in the eyes of the Elias Sports Bureau, Major League Baseball¡¯s official record keeper, there are in fact two fewer members of the 2,000-RBI club.

The difference between the two lists mostly comes down to this: RBIs did not become an official statistic until 1920, so Elias does not count RBIs accrued before that date. Baseball-Reference states that Anson had 2,075 RBIs in his playing career from 1871-97, but MLB.com has him at 1,879 because his RBIs in the National Association from 1871-75 aren't counted. Elias doesn't give him credit for any RBIs because it was before 1920. Elias' designation also knocks out more than 200 RBIs from Ruth¡¯s Red Sox tenure from 1914-19. Baseball Reference, however, retroactively added RBIs prior to 1920, based largely on research originally spearheaded by Pete Palmer for the Total Baseball encyclopedia series.

(You may also notice that Elias has Gehrig with one fewer RBI than you'll see listed on Baseball Reference. Elias¡¯ official RBI total for Gehrig has changed several times, even within the four years since Rodriguez passed him on the all-time list. Due to the uncertain nature of record keeping in the early part of the 20th century, some discrepancies exist between the stats provided today by different historical data providers.)

For context: Four hitters have clubbed 700 homers, with Pujols (703) the latest to join the club. The 4,000-hit club also has just two members in Pete Rose and Ty Cobb, along with Ichiro Suzuki if you count his hits from Nippon Professional Baseball. The few hitters with 2,000 RBIs are truly in some rare company. Here's a quick look at the top five all-time RBI leaders by Elias' definition.

1) Hank Aaron: 2,297 RBIs
Aaron never came anywhere closer to the single-season RBI record (Hack Wilson: 191), but -- just as the manner in which he compiled his 755 home runs -- he was incredibly consistent. Hammerin' Hank averaged 111 RBIs per year from his age-21 season in 1955 through his age-37 campaign in '71, and he drove in less than 60 just once (his final season in '76) over 23 years in the big leagues.

2) Albert Pujols: 2,218 RBIs
Pujols' tenure with Los Angeles didn't quite match his first stint in St. Louis, but his head start with the Cardinals laid the foundation for a 2,000-RBI career. Prince Albert averaged 121 RBIs per season over his first 11 years in St. Louis, dipping below 100 just once in 2011, his final season before signing with the Angels. That was the year he captured his second World Series ring, of course, making for the perfect consolation. Pujols had a magical 2022 season in his return to St. Louis, hitting 24 homers and driving in his final 68 runs at age 42.

3) Alex Rodriguez: 2,086 RBIs
A-Rod was just as consistent, as he's tied atop the all-time leaderboard with Pujols with 14 100-RBI campaigns. He's also MLB's all-time leader with 25 grand slams. Rodriguez's 2,000th and 2,001st RBIs came on a two-run homer off Orioles pitcher Bud Norris on June 13, 2015, and he would collect his 3,000th hit on another homer less than one week later.

4) Barry Bonds: 1,996 RBIs
Bonds actually owns the second-highest season for home runs without reaching 100 RBIs, when he clubbed 45 dingers and drove in 90 -- thanks, in large part, to his 148 walks (61 of them intentional) -- in 2003. He would have surely blasted past 2,000 RBIs had opposing pitchers simply chosen to pitch to him more often than they did.

5) Lou Gehrig: 1,994 RBIs
Gehrig was also a sure bet to cross 2,000 before amyotrophic lateral sclerosis (ALS) brought his career to an abrupt end in 1939. Not only did The Iron Horse play every single day; he drove in a dizzying amount of runs, averaging an incredible 150 RBIs per year from his first great season in '26 through his last fully healthy campaign in '37.