Offense is advantage Diamondbacks: In games through 30 June, the Diamondbacks’ 5.19 runs per game ranked third, while the Royals 3.28 runs per game ranked last in the Majors (Baseball Reference).
Bullpen Pitching is advantage Royals. In games through 28 June, the Royals ranked about average (9th in OBP, 12th in SLG, and 11th in wOBA) while the Diamondbacks ranked low (26th in OBP, 30th in SLG, and 27th in wOBA).
Both teams have a lot of blown leads. In games through 30 June, the Royals blew leads in 23 games while the Diamondbacks blew leads in 28 games.