The Underarm Serve: Errani’s Masterstroke

Most of Howie’s midweek group are appalled at Errani’s serve. They are purists, to say the least. Some even question whether it’s legal.

But the results speak for themselves: Sara Errani, at 38, remains a force on the pro tour, a Golden Slam-winning doubles specialist who has mastered a serve few dare to try.

Sara Errani stood at match point in the Billie Jean King Cup semifinal, staring down Iga Świątek, one of the world’s best. Then, she served—underarm. What followed was not a gimmick or an act of desperation. It was a masterclass in adaptability, executed by a player who has turned a perceived weakness into one of the game’s more potent weapons.

Michael Chang: The Original Underarmer

Long before Sara Errani brought the underarm serve into the women’s spotlight, Michael Chang executed one of the most famous underarm serves in tennis history—on match point, no less. It was the 1989 French Open, and Chang, just 17 years old, was battling severe cramps in a fourth-round clash against world No. 1 Ivan Lendl. Barely able to move, Chang pulled out an underarm serve late in the fifth set. It caught Lendl completely off guard. Chang went on to win the match and ultimately the tournament, becoming the youngest male Grand Slam champion in history.

Reframing Weakness into a Weapon

Errani’s story is unique. Standing at just 5’5”, she lacks the height and power of today’s big servers. For years, her serve was mocked, criticized, even meme’d. But instead of hiding from it, she embraced the challenge, building a tactical repertoire around placement, variation, and surprise.

The underarm serve wasn’t born from whimsy—it was born from necessity. When her regular serve began collapsing under pressure—most notably with severe yips in 2019—Errani made a radical decision: she would serve underarm entirely during a tournament in Paraguay. The reaction was brutal, but the outcome was revealing: she reached the final.

A Strategic Statement, Not a Trick Shot

While players like Nick Kyrgios and Alexander Bublik deploy the underarm serve for flair, Errani does it with a surgeon’s precision. Against Świątek, it wasn’t about showmanship. It was about starting the point on her terms—controlling tempo, rhythm, and positioning.

As she explained:

“I don’t try to make winners. I just try to make kick, make slice… sometimes is better for me to serve not that fast, because if you serve fast the ball is coming back faster.”

Is It Legal Under the Rules?

Yes—the underarm serve is completely legal under the rules of tennis. The only requirement for a valid serve is that the ball must be hit before it touches the ground and must land in the appropriate service box. There is no rule that requires the server to strike the ball overhand. As long as the motion is continuous and the ball is not thrown and allowed to bounce, the underarm serve is fair game—even in professional play. That’s what makes it such a disruptive, underutilized weapon.

Why It Disrupts Timing

What makes the underarm serve so difficult to return is that it fundamentally breaks the rhythm most players rely on. At every level of tennis, returners are trained to read toss height, racquet swing, and body rotation to time their split step and initiate their backswing. The underarm serve removes all of that. It comes slower, lower, and earlier than expected—often before the returner has even completed their split.

This plays havoc with players who “quick hit” the return—those who rely on the ball’s pace to time a sharp, early contact. Suddenly they’re forced to generate their own power on a floating ball that arrives below knee height, with no predictable trajectory. The result? Mis-hits, awkward footwork, or mistimed aggression. Even top pros like Daniil Medvedev and Taylor Fritz have been caught out by Errani’s underarm, proving that disruption can be just as deadly as power.

Expect Scorn

Even so, if you decide to use the underarm serve, be prepared for derision and scorn. Tennis purists often view it as unsportsmanlike or beneath the standards of “proper” play. You might face eye-rolls, muttered comments, or even outright ridicule—from opponents, spectators, and yes, even your own teammates. But as Errani has proven time and again, winning changes the narrative. If you’re confident in your intent, unbothered by tradition, and smart about when to deploy it, the underarm serve can be a bold, effective answer to pressure—not a sign of weakness.

From Panic to Process: The Psychological Shift

Errani’s journey with the serve reflects the essence of mental resilience. Her coach advised her to serve underarm for a full tournament to liberate her mind. That decision echoes the “Practice Under Pressure” and “Adaptive Strategies” discussed in sports psychology: face the fear head-on, and reclaim control.

She also leans on breathing routines and visualization, managing match-day nerves that once crippled her ability to toss the ball.

For Competitive Players

The underarm serve isn’t a shortcut. It’s a reminder that tennis intelligence can outplay raw firepower.

Errani’s decision to lean into discomfort turned her serve into a disruptor—a shot that rattled Świątek, flummoxed Fritz, and helped Errani secure a Golden Slam in doubles.

Want to Try It?

Practice under pressure. Don’t save it for matches. Test it during high-intensity drills.
Pair it with variety. Mix it with slice and kick serves to create unpredictability.
Use it selectively. Against deep returners or when protecting a second serve.
Own the moment. Confidence is everything. Commit, don’t hesitate.

Wrap

The underarm serve isn’t weak—it’s wise. Errani didn’t just revive a controversial shot—she redefined it.

The Underarm Serve: Errani’s Masterstroke