It's hard to figure Nick Kyrgios out. In a third meltdown in as many years in Shanghai, the Aussie got riled up when the umpire warned him that his effort was "borderline" after he didn't try for a return. He would lose his opener in three sets to Bradley Klahn.

It's the latest incident for the 23-year-old but, until this point, his 2018 season overall has been a big improvement in behavior. While many still believe he has incredible potential, including Roger Federer, others think that time is running out if he doesn't mentally get it together.

The world No. 38 has won four career ATP titles, most recently in Brisbane this year. In his career, he has made just two ATP Masters 1000 semifinals and reached the final in Cincinnati in 2017. His best major performances have been two quarterfinal showings.

Do you think Kyrgios will ever win big?