Blue clay surfaces nixed by ATP LONDON, June 23 (UPI) -- Blue clay surfaces, first used in competition last month in Madrid, have been banned for future ATP Tour tournaments, the tour's chief said Saturday. The blue clay was used on a one-year experimental basis at last month's Madrid Open. Such surfaces make tennis balls easier to see on television. But the surface was met with complaints from superstars Rafael Nadal and Novak Djokovic among others. Both voiced displeasure about the court conditions in Madrid as they each made earlier-than-expected exits. "After careful consideration, I have decided that blue clay courts will not be allowed next year," ATP Executive Chairman and President Brad Drewett said in a statement. I very much believe in innovation and exploring ways to enhance our sport. While the blue clay may have offered better visibility on television, there were clearly issues with the quality of the courts in Madrid this year, which were not acceptable at an ATP World Tour Masters 1000 tournament, one of our top events worldwide.