The upset caused a big shock to the tennis world on twitter. Fans made claims that since winning a grand slam and becoming one of the top ranked players in the world, Wawrinka has lost the motivation to do well, while others even claimed that he has become too arrogant, which is stopping him from succeeding.
My perspective on the upset is completely different. To me Wawrinka in 2014 is still the same guy as Wawrinka in 2012.
Although he has made several appearances in the late rounds of majors in 2013 and 2014, Wawrinka is still just as susceptible to upsets as before. I've said since 2011 that Wawrinka is one of the most inexplicably inconsistent and completely unpredictable players on the men's tour. He can shock the world by winning the Australian Open or he can shock the world by losing in the first round of the very next major he plays.
The biggest thing that has changed between 2012 and 2014 is the expectations of the fans, who now look at Wawrinka as a grand slam champion and the No. 4 player in the world. They expect him to succeed with the same regularity as Andy Murray did in 2011, when he was the No. 4 player in the world.
While the Swiss No. 2 has posted many good results at tournaments in the last 21 months, he is not a different person than the guy that was the only player in the top 20 not to win a title in 2012. Thus, I'm no more surprised when Wawrinka loses to Ito than if any other top 20 player had lost to Ito.
For most players, this isn't the case though. Normally, as a player's ranking goes up, their number of losses to players ranked lower than a certain point go down. I picked top 20 as that certain point for Wawrinka, since almost any loss for Wawrinka in the last seven years to a player ranked outside the top 20 would be considered an upset mathematically.
The x-axis on this graph is Wawrinka's year-end ranking, while the y-axis is his number of losses Wawrinka has had to players ranked outside the top 20. What we would expect (and see with most players) is a strong positive correlation between being ranked lower and losing to players outside the top 20 more often.
However, what we see with Stan is that in the last seven years is that there is almost no correlation between ranking and losses to players outside the top 20, and the slight correlation that exists is actually negative!
In 2013, Wawrinka was ranked No. 8 in the world but lost just 10 matches to players outside the top 20 in 23 tournaments. However, in 2010, Wawrinka played in 20 tournaments and finished the year ranked No. 21, but only lost five matches to players outside the top 20.
So the math clearly shows that the frequency with which Wawrinka suffers shocking losses has almost no relation to what his ranking is. Yet people are expecting him to reach the quarterfinals or better of every tournament now simply because his ranking is higher. No wonder fans are frustrated with Wawrinka!
Now, there is Marin Cilic, who just won his first grand slam. We shouldn't expect his results in the next 12 months to look much different that the results he was recording in the first eight months of this season. Instead of thinking he will win every tournament now because he won a grand slam, realize that he is still the same person that was excited just to reach the final of a 500 event just seven months ago.