question: List some influential water polo coaches from the past 20 years. I want a concise answer, not exceeding 50 words. Ensure to include at least one coach who has contributed significantly to youth water polo development.
answer: Influential water polo coaches include Ratko Rudić, known for his international success; Dejan Udovičić, who revitalized the USA team; and John Vargas, recognized for his contributions to youth development and collegiate coaching at Stanford University.