Alexander Zverev's second serve is making it all happen

The second serve is not the first shot you think of when looking at a tennis player, but Alexander Zverev’s tremendous improvements on this critical shot have helped him ascend to the Top 10.

“If you look at all the stats in men’s tennis that most closely correlate to success, it’s the second-serve points won,” Tennis Channel analyst Justin Gimelstob told Baseline. “It shows you how much his [Zverev’s] second serve has improved. It shows you how much his game has improved in defending his second serve and it shows you how much his movement has improved. It shows you everything.”

Just two years ago, Zverev, who ended 2015 as the world No. 83, was 86th on the ATP World Tour in rate of second-serve points won at 47.4 percent. As he jumped into the Top 25 in the rankings last year, he rose to 56th-best.

But this season, the seventh-ranked player on the ATP World Tour has joined the sport’s elite, winning 55.3 percent of his second serve points, which is good for eighth on tour. The question is, how?

Early on in his career, Zverev’s second serve was usually a rolled-in kick serve, creating a sense of predictability for opponents. Over time, the German has become far more aggressive with both his racquet-head speed, serve variety and spot selection. It has shown in a season of success, most recently last week, in Montreal, where he earned his second Masters 1000 trophy.

“He’s one of the most aggressive second servers there is,” Gimelstob said. “Obviously he has a great motion. He’s tall so he gets extra margin...He’s got the guts to go for it and the game to back it up when it does come back.”

The toughest service game for Zverev in his Rogers Cup final victory against Roger Federer was in the second game of the second set, when he faced the only three break points held against him in the entire match. A high-pressure moment like that would usually make a player nervous—nerves usually cause players to slow their arm swing and racquet head speed down—yet look at what he delivered on game point:

That second serve, struck at 196 kilometers per hour (or 122 mph), didn’t allow Federer to get a clean hit on his forehand return, virtually neutralizing the point. That is tough to do considering the Swiss was looking to be aggressive on the return, armed with one of the best forehands in the sport.

Now take a look at a second-serve kicker that Zverev hit in a point that he would eventually lose:

Sure, Zverev lost the point. But Federer was forced way behind the baseline to get a swing on the return, giving up court position and making it tougher for him to land his shot deep in the court.

Zverev’s aggressive racquet-head speed not only brought the ball up and down more safely than if he slowed his arm swing down, but caused a dilemma for Federer throughout the match—should he stay close to the baseline and attempt to take the high-bouncing kick or a harder second serve early with a shorter swing, or back up to produce a fuller stroke? Neither scenario is an easy one for the returner.

While Zverev missed a fairly simple short ball in the last video, he was in an excellent position to win the point thanks to his second serve, which helped in allowing him to control play in the match from the get-go. Overall, Zverev won a massive 61 percent of second serve points against Federer in the final.

Andy Roddick, who had one of the best second serves in the history of tennis, won 56 percent of his second serve points on average throughout his career. Nobody expects that sort of statistical performance by Zverev every match, but it certainly shows that he has come a long way in a very short amount of time.

—WTA Western & Southern Open Live: Watch all Western & Southern Open action live from Cincinnati on Tennis Channel Plus.

—WTA Western & Southern Open Encore: Can’t make it to Cincinnati? Watch all the coverage On Demand, including match play from Venus Williams and Simona Halep.

—Tennis Channel Academy: Learn from the game’s best and watch Tennis Channel Academy on Tennis Channel Plus.

—Get Tennis Channel Plus for 650+ live events all year long.

—Tennis Channel Plus is available on any streaming device, on mobile, always on the GO (desktop, iOS, Android, Apple TV, Roku and Amazon Fire). Subscribe today at BuyTCPlus.com.