A tennis player’s progress is not always a straight line— more often it’s marked by peaks and valleys.

But the overall trend for Jack Sock has been upward— perhaps something like a 45 degree angle— since he turned pro in 2011.

The past two months?  The career trajectory has become visibly steeper.

Top Down: Led by Sock, Stephens, and Vandeweghe, U.S. Player Development Trending Up

Sock blazed his way into the ATP Finals with a victory in the Paris Masters and reeled off 7 straight wins in 3rd-set-decider matches before going down fighting in the semis to eventual champion Grigor Dimitrov.

The reality of his game is starting to emerge as more than its reputation— a style that’s always drawn heavy comparisons to Andy Roddick, his fellow Nebraska native.

Sock hits with more spin than Roddick did, and he’s better at the net.

This is just one American success story from the 2017 tennis season.  It’s a phenomenon that is jumping up and nipping at tennis in the backside.

As for the women, Sloane Stephens won her first major at the US Open, proving it’s not just Serena’s sport for the Americans anymore.  CoCo Vandeweghe propelled the United States to its first Fed Cup in 17 years.

Is this real, or just a bump?

One way to assess that question is to look at the junior levels of the sport.  A team is only as good as its farm system.

On a conference call last week, USTA General Manager of Player Development Martin Blackman presented developmental coaches with some uplifting metrics (see below):

The chart represents where U.S. players of both genders showed up in the upper tiers of each level 7 years ago versus where they are now.

To be fair, tennis is a global sport.  The U.S. avails itself of coaches from around the world to help develop its players.  

Still, player development in the United States appears to be on an upward trajectory of its own.