Wozniacki was key to his daughter's rise to No. 1, but many doubt she has the offensive weapons needed to win a major. The Woznicaki camp brought in Spanish coach Ricardo Sanchez, but fired him after the 2012 Australian Open after just two months on the job. "If Caroline finds a coach that she thinks might suit her, we'll take him," Piotr said after dismissing Sanchez. Here's a look at some of the most notable tennis dads who have coached their kids.