SI.com Staff
Sunday September 13th, 2015

How did Flavia Pennetta go from being the 26th-seed to becoming the 2015 U.S. Open champion? Let’s look at her serving and returning numbers for 2015 coming into the U.S. Open and what she accomplished during the tournament:

The old saying "You're only as good as your second serve" can apply to Pennetta's performance throughout the tournament. Pennetta improved her performance on her own second serve and returning second serves at the U.S. Open against opponents that included a former U.S. Open champ in Sam Stosur and two players ranked in the top 5 in the world in Petra Kvitova and Simona Halep. Improving her second serve performance from 45% won to 54% won helped her increase her service games won to 77% for the tournament. Improving her return of second serve improved her return games won percentage to 47% from 37% for the tournament. 

Check SI.com's 2015 U.S. Open data hub page throughout the whole tournament for the latest data-driven infographics and charts from IBM, the official technology partner for the U.S. Open. IBM captures and analyzes the data that powers all of the Grand Slams, as well as the digital platforms that extend the experience to fans around the world.

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