It always surprised me how Charley Lau could be such a great hitting coach with minimal success as a player. One of our own in the mid to late 1950's. Charley Lau Stats, Height, Weight, Position, Rookie Status & More | Baseball-Reference.com He became reknown with the royals and his number 1 protege George Brett.What ever happened to "see the ball, hit the ball?"
Anyway. The first hitting coach I ever remember being touted as a "guru" was Charlie Lau. And he was the Royals' BC in the 1970s. The Royals may have been the first team in MLB to break the game down to its components and to promote a "method" of approaching baseball, (or maybe the Brooklyn Dodgers were first) more from the hitting and defense sides than pitching, which consisted of, as I remember, as an eclectic group of arms back then as any other team. (Splittorff, Leonard, Busby, and others -- nothing that outstanding; just solid)
First pitching coach guru I remember: Johnny Sain, who was moved around because managers considered him a rebel of sorts. Mayo Smith, that managerial icon, fired Sain and they Tigers' pitching staff quickly declined as a result.
End of rant.
I am of the opinion that Johnny Sain was the greatest pitching coach the Tigers have had throughout the teams history. Mayo was intimidated by Sain and the control he had over the pitchers. Ego gets in the way of success at times.