When Nike said on Thursday that John Donahoe was stepping down as chief executive officer, his exit from a rocky tenure offered a brutal reminder to corporate boards: Focus on what a company's core business is when looking for a new CEO.

Elliott Hill started at Nike as an intern in 1988 but steadily scaled its ranks, banking on values of grit and hard work ingrained in him as the son of a single mom in a working class Texas neighborhood.

Athletic equipment and sportswear giant giant Nike (NKE) is as big name there is in its chosen business. It makes all sorts of shoes, uniforms, basketballs and related gear. Its best-known product is the Air Jordan line of basketball shoes.