Jorge Posada, a mainstay of the New York Yankees for well over a decade and one of the best catchers in that, or any, team’s history recently announced his retirement. Posada will now be counted among those Yankee greats like Whitey Ford, Bill Dickey, Thurman Munson, Lou Gehrig, Phil Rizzuto, Mickey Mantle, Bernie Williams and Joe DiMaggio who spent their entire careers with the Yankees never playing even one game for another team. It is likely that in the next few years, Posada’s longtime teammates Derek Jeter and Mariano Rivera will join him in this group.

Rivera is the second member of the team’s vaunted core four, which also included Jeter, Rivera and Andy Pettitte, to retire. The core four was always a bit of a misnomer because it seemed a slight against Williams who starred on four Yankee championship teams, spent his whole career with the Yankees and played alongside Posada, Jeter and Rivera for as long as Pettitte, who had a three year hiatus with the Houston Astros, did.

Nonetheless, the core four is now down to two players, Jeter and Rivera. There is almost no precedent for the joint career arc of these two players. 2012 will be their 17th year together. It is unusual for any two teammates to spend 17 years playing together, even more unusual if these players are Hall of Famers, as Jeter and Rivera are certain to be, and even more unusual if these two players are both among the greatest ever at their position, as Jeter and Rivera are. Both Jeter and Rivera made their debuts in 1995, but came to the big leagues for good in 1996. Moreover, both Jeter and Rivera were in the Yankee minor league system, at various different levels between 1992-1995.

Jeter and Rivera were very different players and personalities, but together they have defined the Yankees since 1996; and for the Yankees this era will always be identified with them. For Yankee fans, having two extraordinary players play together for their entire careers has been something very special. Seeing one all time great play his entire career for one team is rare, but seeing two players do it together for this long is almost never occurs. For fans of other teams, however, it is also a reminder of the inequality in baseball. Every time either of these stars were seeking a new contract, the Yankees quickly and unambiguously outbid any possible competition, making it easy for Jeter and Rivera to choose to remain Yankees for their entire careers.

There is something to this, but it is also an oversimplification. In recent years, a number of teams have sought, with some success, to keep their home grown stars together, but not for quite this long. The Astros, for example, where able to keep Craig Biggio and Jeff Bagwell, who was originally a Boston Red Sox prospect, together during their entire careers. Moreover, in order to retain Hall of Fame talent, a team has to be able to develop it. The Yankees did this very well in the early 1990s developing two certain Hall of Famers and three other borderline candidates within a period of about five years.

Jeter and Rivera, despite Jeter’s poor performance during much of 2010 and the first part of 2011, have also been very good old players. Thus, while it is possible to argue that they have been overpaid in recent years, and will be overpaid during the next few years, they won’t be overpaid by much. Jeter still produces reasonably well for a shortstop and Rivera is still one of the top closers in the game.

Ironically, while loyalty to Jeter and Rivera, as well as Williams and Posada, albeit to a different extent, may have been grounded in things like engendering fan loyalty and avoiding the negative press which would have happened if any of these players had gone to another team, these decisions all helped the Yankees. Between 2002-2008 when all four of these players, except for Williams after 2006, were still with the Yankees, being extremely well paid, and showing signs of age in some cases, the Yankees never won a World Series. However, it would be difficult to argue that any of these players cost the Yankees that opportunity. On the contrary, they all contributed during these years. In fact, the failure of the Yankees to resign Andy Pettitte after 2003, might have cost them a chance to win championship in on of the three seasons, 2004-2006, while Pettitte was gone.

In 2011, Jeter’s 3000th hit and Rivera’s record breaking 602nd save were among the major stories for the Yankees. This year will be filled with similar milestones as Jeter and Rivera secure their positions on various all-time and Yankee lists, but the era that they have defined is almost over. The Yankees have the resources and the savvy to keep contending, but it will be a lot tougher without a core four staying together for more than a decade.

Lincoln Mitchell