Under the blazing sun on tennis courts around the world, most players strive for the textbook serve—a fluid, powerful motion designed to intimidate opponents and rack up aces. Yet Federico Delbonis, an Argentine professional, has carved out a unique niche with a serving style so unorthodox that it confounds even the game’s most experienced servers. His serve, often described as awkward or “insane,” has become something of a curiosity within the tennis community, standing out amid a sea of polished techniques.

To understand the peculiarity of Delbonis’ serve, it helps to listen to what some top servers have said about it. John Isner and Sam Querrey, two players renowned for their dominant serving games, have publicly commented on Delbonis’ delivery. On the tennis podcast Nothing Major, Isner quipped about the extraordinarily high ball toss Delbonis uses, dubbing it “insane.” Querrey wasn’t far behind, labeling it “probably the worst-looking serve of all time.” Their remarks may sound humorous, but they also underscore a broader truth: Delbonis’ serve defies convention, yet it remains effective.

To the casual observer, Delbonis’ numbers might not jump off the page when compared against the towering ace counts of Isner and Querrey. Isner holds one of the highest ace tallies in history, with over 14,000 career aces, while Querrey has nearly 9,000. Delbonis’ ace count, hovering around 1,200, pales in comparison. But a deeper dive into the statistics reveals more nuance. Despite having fewer aces, Delbonis has demonstrated greater consistency and control in critical areas. For example, he commits significantly fewer double faults—just over 1,200 in his career—compared to Isner’s near 1,800 and Querrey’s more than 2,300. Furthermore, Delbonis’ first-serve winning percentage stands impressively at 69%, a figure that sits notably between Isner’s 79% and Querrey’s 59%. This demonstrates that while Delbonis may not rely purely on speed or sheer power, his serve produces results more often than not.

Delbonis’ serving style is a classic example of a double-edged sword. The extremely high toss and unconventional mechanics can lead to stunning winners and surprise opponents unprepared to read his rhythm and spin. On the flip side, the risk of inconsistency looms large, with a higher chance of faults on any given day. This volatile mix characterizes a player willing to embrace idiosyncrasies rather than conform to the polished mold demanded by most coaching philosophies.

Historically, tennis has seen many players whose techniques bucked tradition and yet proved successful, from André Agassi’s open-stance forehand to Pete Sampras’ unique serve motion. Delbonis fits into this lineage as a reminder that tennis is as much an art as a science, and innovation or individuality sometimes triumphs over textbook form.

Delbonis has a notable history of holding his own against top competition, particularly resonating on clay courts, which suit his style and baseline game. One memorable match came against John Isner himself at the 2014 German Open, a clay tournament where Delbonis managed to upset the American giant. This victory showcased his ability to harness his atypical serve and game plan effectively, even under intense pressure. Yet, when the two met again eight years later at the 2022 US Open—played on hard courts with Isner holding home advantage—the result tipped in favor of the more conventional server, highlighting just how surfaces and conditions influence the viability of Delbonis’ approach.

Federico Delbonis’ career is a testament to persistence and individuality in a highly competitive, sometimes rigid tennis world. Born in Azul, Argentina, Delbonis rose through the ranks largely on the strength of his baseline game and extraordinary mental toughness. Turning professional in 2008, he has consistently been a strong contender on the ATP Tour, particularly on clay—a surface where his heavy topspin groundstrokes and patient point construction shine. Beyond his serve, Delbonis is known for his strategic approach, often outmaneuvering opponents with patience rather than overpowering them.

In a sport where many players prioritize biomechanical perfection and coaching-driven mechanics, Delbonis’ refusal to reshape his serve stands out as a refreshing anomaly. It reminds fans and aspiring athletes alike that there isn’t just one blueprint for success in tennis. Sometimes, the path less traveled—marked by resilience, personal expression, and unorthodox ingenuity—can yield unforgettable moments and a career marked by true individuality. In embracing the unconventional, Federico Delbonis has carved a legacy uniquely his own, proving that success isn’t merely about how a serve looks but rather how effectively it wins points.