Day 4 of the 2015 US Open and the tournament has already brought a lot of surprises. While we all might have expected Nick Kyrgios to exit with flare in the first round, few of us would have anticipated that the first round would say farewell to so many of the seeds. The ladies’ draw feels especially bare after 11 of 32 seeds (34%) did not advance to the second round–Stephens (29), Pavlyuchenkova (31), Pliskova (8), Kuznetsova (30), Suarez Navarro (10), Jankovic (21), Ivanovic (7), Safarova (6), Begu (28), Bacsinszky (14), Cornet (27). But is this level of upsets really that surprising?
One way to try to answer this is by comparing to the upset patterns in previous years. If all players performed to their seeding, we know exactly how many seeds should remain in each round. This is shown by the “Expected” line in Figure 1. In the past ten years of the US Open, the WTA has not performed to expectation in any of the early rounds. But the tour has generally been much closer than in 2015. The only other year that was close to the number of seed loses in the first round was in 2012, where only 22 seeds remained by the second round. So 2015 is off to a surprising but not shocking start.
Overall, the seed survival curve suggesting the most topsy-turvy tournament from 2005 - 2014 was in 2009. But that could change, if the seeds continue to fall this year.