Mike Trout
On April 17, 2015, Trout became the youngest player in MLB history to reach 100 home runs and 100 stolen bases. He was 23 years and 253 days old when he reached the milestone, passing the previous record-holder, Alex Rodriguez, who had achieved it at the age of 23 years and 309 days in 1999. Trout led off the 2015 MLB All-Star Game with a home run, becoming the fourth player in All-Star Game history to do so. For the second year in a row, Trout won the All-Star Game MVP Award, becoming the first player ever to win it in consecutive years. On September 22, Trout hit his 40th home run, becoming only the second Angels player to hit 40 home runs in a season. Trout led the AL in WAR for the fourth straight year.
Mike Aulby
Aulby joined the PBA Tour in 1978 and captured his first title and Rookie of the Year honors in 1979. His first title was a major in the 1979 PBA National Championship, as he became the youngest player (19 years, 83 days) to ever win a PBA major. That record stood until , when Anthony Simonsen (19 years, 36 days) captured the USBC Masters. On June 12, 1985, Aulby became the youngest player in PBA history (25 years, 89 days) to reach ten career PBA titles, achieving that plateau one day faster than Wayne Webb. That feat would be bested by Pete Weber in 1987, when he won his tenth title at age 24 years, 247 days. As of 2018, Aulby is still the second-youngest on this list.