Killebrew was a bonus baby, meaning he basically watched the Senators/Nationals from the bench for several seasons until they finally gave him regular at bats. As expected, his batting average was lower than most guys in the league, but the 42 homers he hit in his first full season was not expected. He'd surpass 40 homers 7 more times on the way to a Hall of Fame career.
Matt, you've done it again! Making quite a statement with just four cards - I hope the return volley heading your way can live up to this!