WISE MEN SAY the first time you feel old is when you look around and realize that most major league baseball stars are younger than you. If that's true, a lot of folks are aging very suddenly. Young studs are everywhere around MLB these days.

Consider the best players in each league and the careers they could have in store. In the NL, that would be 23-year-old Bryce Harper, about whom my colleague Jayson Stark has written: "He's a blend of Pete Rose and Reggie Jackson, as if that were even possible." Actually, it was possible; his name was Frank Robinson. As in the Triple Crown -- winning Frank Robinson who hit 586 career home runs and won the MVP in both leagues. He happens to be the best statistical comparison to Harper in baseball history, according to Baseball-Reference.com. In the AL, it's Mike Trout, 24, and his best comp is Mickey Mantle. As in Mickey Freaking Mantle.

Beyond them, the parade of high-grade youngsters just keeps marching. Jose Altuve, Nolan Arenado, Kris Bryant, Madison Bumgarner and Gerrit Cole were All-Stars last year. Mookie Betts and Carlos Correa will be for years to come. And that only takes us through the first three letters of the alphabet.