Bryce Harper of course left the Nationals last offseason in order to sign a $330 million contract with the division-rival Phillies. Harper's first season in Philly was productive (35 home runs and a 125 OPS+ in 157 games) while still not being quite up to his career standards. The Nationals, meantime, recovered from a slow start to make the postseason and then battle their way to the first World Series in franchise history.
Obviously, that the Nats achieved unprecedented success in their first post-Harper season has led a number of observers to confuse correlation and causation. Whether the Nationals would've made the World Series with Harper on the roster is unknowable, but he's a much better player than Adam Eaton, who replaced him in right field in Washington. Of course, the Nats probably wouldn't have signed Patrick Corbin if they'd been able to re-up with Harper, so there's a discussion to be had around allocation of resources. In any event, how Harper views the success of his former team is a source of ongoing curiosity, and Jayson Stark of The Athletic went straight to the source to find out.