Everyone knows that John Isner's biggest weapon is his booming serve. But what is sometimes overlooked is just how good it is, and for just how long. The 6'10" American has been crushing service stats for a decade.

He's often threatened at the top of the ATP service stats leaderboard by Ivo Karlovic, but the Croatian is ranked No. 101 while Isner is No. 10.

Isner leads the ATP for highest first-serve percentage (69.5 percent) and percentage of service games won (93.6 percent). He's second for average aces per match with 22.5 (Karlovic is 22.7).

In 2018, Isner hit 1,213 aces, second only to his personal best of 1,260 in 2015 (Kevin Anderson was second this year with 1,082) Isner has now finished first for most aces in a season in six of the last 10 years. In Houston this year, Isner reached his 10,000th ace, becoming just the fourth man in ATP tracking history (since 1991) to accomplish the feat (the others are Karlovic, Roger Federer and Goran Ivanisevic).

This year was Isner's best career season. The 33-year-old won his first ATP Masters 1000 in Miami and made his ATP Finals debut. It also marks the first time Isner has finished a year inside the Top 10, with 2015 being his previous best finish at No. 11.