It hasn't reached the chaotic level of Wimbledon 2013, but the French Open had a good amount of upsets in the first four rounds this year. The top three women's seeds are all gone, and three of the top 11 men's seeds went out in the first round. There have been some ripple effects in both cases, and some players have elevated their game and find themselves with much better odds than when the tournament began.
Let's take a look at the odds for the remaining players. (Dashboarding again provided by John Mathis.)
Rafael Nadal has a 49 percent chance of winning the tournament at this point, Novak Djokovic is at 40 percent, and the other six remaining players combined are at 11 percent.
When you compare Nadal's and Djokovic's odds to when the tournament started, Nadal's win odds have gone up by 10 percent, and Djokovic's have only gone up five percent. That's partially because Nadal has looked very strong -- his worst set was only winning by two games, whereas Djokovic had a couple of average wins in the first two matches and dropped a set to hard-courter Marin Cilic in the third round. In addition, Nadal has been the beneficiary of all the big men's upsets (Nicolas Almagro, Stan Wawrinka, Kei Nishikori), and Djokovic's remaining path to the final is one of the toughest he could have received.
If you want a dark horse to win, don't sleep on David Ferrer. He's had healthy scores in the early rounds and stands to have a soft semifinal matchup if he gets past Nadal in the quarterfinals.
At 40 percent, Maria Sharapova is the heavy favorite with Serena Williams out of the tournament. But her advantage isn't as significant as you might have thought. She's basically guaranteed to have a tough out in the final; all four of her potential opponents are ranked in the top 12 of the Advanced Baseline clay rankings.
Meanwhile, AB preview star Simona Halep (21 percent chance of winning) is the solid favorite to make the final now that Ana Ivanovic is out. She's lived up to her billing thus far, and her draw has cooperated since the tournament started. Sara Errani (14 percent) is probably the next biggest favorite after those two, Carla Suarez Navarro (10 percent) remains my favorite dark horse to make a finals run. I had her as the No. 7 clay player going into the tournament, and her path has been cleared significantly by upsets to the seeds she would've faced.