I stumbled across something strange while researching my article on brothers in baseball last week:

According to our player cards (and every other source of player bio information on the internet), Wilton Guerrero and Vladimir Guerrero were born less than four months apart. But according to many other internet sources of player bio information, Wilton Guerrero is Vladimir Guerrero's older brother. This would seem to present a problem. Human gestation periods being what they are, three-plus months doesn't seem like nearly enough time to give birth to a borderline Hall of Fame baseball player.

There are three possible explanations for what's happening here. Well, maybe more like four, but I'm putting two under the same subheading:

Vladimir Guerrero's mother was even better at making babies than Vlad was at baseball.
This is plausible, because Vlad, who has eight children of his own, comes from a long line of prolific reproducers. Vlad's maternal grandmother had 14 children, and his maternal grandfather, who was clearly trying to maximize his odds of making major leaguers, had 30 children, which is almost Unfiltered-worthy on its own. The Guerrero family tree must be amazing! Still, it seems unlikely that Vlad's mother made babies almost three times as fast as the average woman, or that someone born that many months premature could survive and grow up to swing at so many pitches outside of the strike zone.

Vladimir and Wilton are half-brothers, like the Izturii and Livan and Orlando Hernandez (and other people who are half-brothers).
This is also plausible, because Vlad has at least four half-siblings. But as best as I can tell, Wilton isn't one of them. This 2007 OC Register profile of Vlad's mother says, "Her life changed drastically when two sons — Wilton and Vladimir — broke into the majors in 1996." This 2004 Seattle Post-Intelligencer piece suggests that Vlad's mother knew the LA area because Wilton had played there. This 2001 Winnipeg Free Press profile strongly suggests that Wilton and Glad grew up together and that Wilton is one of Vlad's mother's sons. And so on. Vlad's mother might have raised Wilton after someone else brought him into the world, but I haven't come across any mention of an other-mother arrangement.

Wilton's listed birthdate is incorrect.
Vlad's birthdate was originally listed as February 9, 1976, not February 9, 1975. This was publicly revealed to be false in the spring of 2009—Guerrero, like many of his countrymen, claimed to be younger than he was when he signed his first contract. When Vlad was believed to have been born in '76, Wilton's birthdate made sense. Once Guerrero's birthdate was changed, Wilton's started looking like either a miracle or another falsehood. But by that time, Wilton was already out of baseball, so either nobody noticed (very unlikely) or nobody cared about correcting it (almost certainly the actual reason). Or maybe, just maybe, someone else enjoyed the anachronism as much as I did and decided to let it live. Way to go, Wilton, you 38-year-old, you.