By Federico Bertelli
Let’s delve into Jannik Sinner’s triumphant journey at the ABN Amro Open and compare it with his 2023 campaign. Service and down-the-line backhands were the keys to victory.
Harder, Better, Faster, Stronger. This is the version of Sinner that his opponents tasted, and it’s also the title of a Daft Punk song; the clip particularly reflects what the rest of the ATP circuit has been thinking about Jannik for some months now: an android emerging after a heavy upgrade. Jokes aside, as the sunshine double is about to start, we thought it wise to rewind and closely examine Sinner’s recent victories.
The focus of our analysis is the Rotterdam tournament: Sinner’s performance was spotless, a feat not seen since 2001 when Lleyton Hewitt, after his victory at Flushing Meadows over Pete Sampras, managed to repeat his success in Tokyo. If the Italian were to win next week under the California sun as well, he would be the first in ATP tennis history to win two consecutive ATP tournaments after the first Slam. But before we dive into the action of the Indian Wells, let’s scratch the surface of Sinner’s victory in the Netherlands a bit. The comparison is plausible as the Italian reached the final in both editions, playing 5 matches in each case.
Draw: The 2024 run was undoubtedly smoother compared to 2023, both on average and in absolute terms. In 2023, the average ranking of Sinner’s opponents increased significantly, from 50.6 in 2023 to 97 in 2024. This means that, in general, we can assume that the journey, at least on paper, was easier. Also, in absolute terms – considering the lowest ranking of an opponent faced – there was a notable difference. In 2023, the insurmountable obstacle was the Russian Medvedev, then the blue’s nemesis and number 3 in the rankings. In 2024, it was a more approachable De Minaur – number 11 in the ATP ranking – against whom the H2Hs have also always been in favour of Jannik.

Break Points: One aspect frequently discussed about Sinner in the last 12 months is his overall growth in all areas: technical, physical, and mental. However, it’s not news that Jannik is mentally tough. Surely, Sinner will continue to tirelessly work on this aspect, as he has always stated, but his starting base has always been enviable. And the results are there for everyone to see. Despite facing a number of break points in the tournament equal to 20 in both 2023 and 2024 – which perhaps was unexpected given the more modest caliber of opponents – the Italian’s response was undeniable. An 80% break point save rate, compared to 65% in 2023 and against an ATP tour average of 61%. (Note: The tour average refers to the average of the last 52 weeks of players who have competed in ATP level tournaments). This figure, among other things, underscores Jannik’s solidity, already above average in 2023.

Service – Overall Statistics: Another aspect that has been frequently discussed is Jannik’s improvement in his service game; indeed, the data speaks for itself. Both in terms of the percentage of first serves in play and in terms of effectiveness in converting such a play situation into a point, Sinner has significantly elevated his game. Working on the percentage of first serves in play was the number one priority to improve the Italian’s game performance, and the efforts of Vagnozzi, Cahill & co. have paid off handsomely. In 2023 in Rotterdam, the percentage of first serves in play was 57%, in line with the general performances recorded by Sinner up to that point. Considering that the ATP tour average was 62%, it’s clear this was an aspect still needing improvement until last year. However, the conversion rate from good became excellent. In 2023 in Rotterdam, the conversion rate of points on the first serve stood at 74%, a figure above the tour average, which is at 72%. In 2024, however, we witnessed a further leap forward, reaching the 80% threshold.

To understand how high this figure is, just look at the leaderboard rankings of the last 52 weeks. In terms of first serves converted into points, 80% is the threshold of absolute excellence. Consider that the two most impressive serving machines ever seen on a tennis court, Karlovic and Isner, had career averages of 83% and 80%, respectively.

Finally, a somewhat surprising data point is the success performance on the second serve. The Italian won 60% of the points on his second serve in 2023, while in 2024, “only” 56%. This rate is evidently more than sufficient to win matches and tournaments, but in 2023, it was not a problem at all, on the contrary.
Delving further into detail and referring to more detailed analyses (for the metrics used, we also refer to the general description found here), the analysis is further enriched. The data reported are the result of TennisViz processing, on data owned by Tennis Data Innovations (TDI).
Service – Detailed Data: The service performance, in terms of precision and reliability of the shot under pressure, has improved from all perspectives. Among the various metrics available, there are some of interest. Starting with the accuracy on the first serve, i.e., the distance with which the serve is placed from the service lines, measured in cm. Referencing a post from the X Tennis Insights account, we have an overview.

In Rotterdam in 2023, Sinner executed this shot with an accuracy of 57 cm, better than what was measured over the course of the year. But in 2024, this figure impressively dropped to a notable 52 cm, in line with that of Hurkacz. We’ll spare you the statistical details, but the result (highly debatable, given the small sample size) is as follows.


Of course, there are many other variables that explain the yield on the first serve, but the inverse correlation between serve speed and precision is not bad, and generally leads us to say that serving at 125 mph with an accuracy of 52 cm, combined with an average quality in return shots, guarantees an untouchable performance of 80% of points won on the first serve. If the quality is that of Sinner’s serving machine, even less will suffice.
Continuing with the quality of the service shown by Sinner, another data point that deserves further exploration is that of unreturned serves, where the opponent fails to return the serve back into play. Here too, Jannik performed exceptionally well, with aces and opponents’ missed returns bringing home an impressive 40% in 2023 and an exceptional 42% in 2024. Remember, in tennis, variations of 1% can make the difference between a solid top ten player and a Grand Slam title winner. To put it in perspective, the ATP average is 38%.

Finally, to conclude the chapter on the serve, one last piece of data, which we’ve kept in reserve for the most deserving who have persisted in reading up to this point; do you know what the percentage of first serve balls on break points was in 2023? And in 2024? Well, we’ll present it to you in a table, and we’ll add nothing more:

In 2023, when serving on break points, the first serve landed much less than usual in crucial moments. In 2024, however, the Italian did not lose his composure at all, serving as if it were any other point… not bad at all.
Performance in rallies: in this case, we rely on [metrics developed by TDI and TennisViz, which obviously carry the ATP brand](https://www.atptour.com/en/news/insights-introduction); (bonus: if you happen to watch a match on ATP TV, these advanced metrics are just a click away, in the stats section of the App).

It’s notable how Jannik has leveled up both in his ability to convert points where he had the advantage (conversion score) and in managing to seize the initiative from opponents when they were in a favorable position during the rally (steal score). Lastly, the final data point: from the baseline, with the current form of Jannik, it’s tough to come out on top, and if we consider his aptitude for turning defense into offense, the puzzle for his opponents is almost unsolvable. Indeed, this explains the overwhelming 56% of points won from the baseline, significantly above the ATP average. This data also finds an explanation in a significant tactical adjustment, the more pronounced use of the down-the-line backhand variation. The backhand crosscourt is already a comfort zone for Sinner, which he can comfortably use to extract points, like a boxer working his opponent with jabs; if we add that now Sinner is also able to find the down-the-line solution at the right moment, again, it spells trouble for his opponents. In 2023, Sinner hit 19.5% of his backhands down the line, while in 2024 this percentage rose to 31.4% in the Rotterdam tournament. A change that helped him tip the scale further in his favor in baseline battles.