US Open 2013: blood testing is the passport to a brighter future, says Andy Murray Now, though, he has adjusted his view. "A few years ago, everyone was like, "We hate it, we don't like it,"" said Murray. But when you see what has happened in other sports, to protect your sport, and to make sure that nothing is going on, you need to have the best doping programme in all of sports. Basically, sport has taken a hit, and a lot of people have lost trust in it. So I think it takes a long time to build that trust back up. I believe in tennis, but the only way for people to see it as being a clean sport is by having the best doping programme in sports. And there's a lot of money in tennis, so we can definitely afford to have a good programme. Meanwhile, the Williams sisters beat the defending champions, Roberta Vinci and Sara Errani, of Italy, 6-3, 6-1 to move two wins away from their 14th Grand Slam tournament title. The sisters play their next doubles match against Czech pair Andrea Hlavackova and Lucie Hradecka. Serena praised the role of Richard Williams in keeping his daughters so successful over so many years. "He's just so innovative, and I think one of the reasons I'm still playing some of my best tennis is because he built my game and my sister's game," she said. He gave us a good foundation. It was solid and it wasn't weak, so we were always able to grow our game. I think that can't really be said about a lot of people in their career. He's a great coach. Even to this day. He wrote me something just the other day, and I really meditated on it and I thought about it, and I thought, "This is what I need to do," and it really helped me out during the match."