With steady performance and reliability, Splittorff became an integral pitching mainstay on the Royals first championship teams. He was the 1973 Royals Pitcher of the Year after becoming the franchise's first 20-game winner. From 1972 to 1980, he averaged nearly 15 wins and 220 innings a year and helped lead the Royals to four postseason appearances. He was part of Kansas City's first draft class in 1968 before the franchise had ever played a game, making him a true original Royal. Splittorff finished his career as the Royals all-time leader in wins (166), games started (392), and innings pitched (2,554.2).