The Sports Frog has an interesting take on the Julio Franco assertion that he will play until 50. They suggest that he has lied about his age all along and is actual much closer to 50 than his baseball age (44) would indicate.
I would tend to doubt that he is the 48 years of age that the Frog suggests. He came up at the age of 23 with the Phils and started for the Indians at the age of 24 (Damn you, Von "5-for-1" Hayes!). If we add 4 years to that, he was not an established major-leaguer until the age of 28.
It is possible and even probable that he shaved a year or two from his actual age when he was signed and the "mistake" has yet to be corrected. He was signed by the Phils on June 23, 1978, just a couple of months shy of his 17th birthday. Sixteen is a very popular age for a young shortstop to claim to be upon signing, especially in San Pedro de Macoris. So anything is possible.
Also, I should have mentioned that Franco missed a good two and one-half years of major-league ball from 1998 to 2001. So his post-40 stats are not as impressive as they might be.