With all due respect to Carlos Alcaraz, the biggest obstacle standing in the way of Novak Djokovic winning his 25th Grand Slam title at the Australian Open was probably not the 20-year-old Spanish phenom who beat him in the Wimbledon final last summer defeated, but lost in the quarterfinals in the early hours of Thursday morning.
It is a 22-year-old Italian named Jannik Sinner who has been giving Djokovic fits in recent months.
Sinner defeated Djokovic in the group stage of the ATP Tour Finals in Turin and then did it again in the Davis Cup semifinals 10 days later, saving three match points and stunning the Serb. Two hours later he did it again in doubles, teaming with Lorenzo Sonego to beat Djokovic and Miomir Kecmanovic and help knock out Serbia.
Djokovic hasn't lost a game in months and has won 33 times in a row at the Australian Open. Sinner took it twice in one day and three times in two weeks and is probably the field's best chance to stop Djokovic from an 11th Australian Open singles title.
“That's what I'm training for, to play against the best players in the world,” Sinner said after eliminating world No. 5 Andrey Rublev in straight sets in the quarterfinals. “He has an incredible record here so it’s a pleasure to play against him, especially in the latter stages of the tournament.”
Sinner defeated Djokovic at Davis Cup (Clive Brunskill/Getty Images for ITF)
It wasn't always like this, not even during Sinner's hot streak in November.
Between Sinner's group stage victory in Turin and Davis Cup victories there was a one-sided defeat in the final of the Tour Championship.
Five days passed between Sinner's victory and the start of the final. Djokovic had done what he so often does. He examined what went wrong in his last game. He watched video footage of that game. He has absorbed data. He consulted extensively with his coach Goran Ivanisevic.
He then took to the court and put in an absolute performance, playing arguably his best game of the year by the numbers.
In short, he figured it out.
More about Djokovic and his incredible 12 months…
The following metrics are the product of ball and player tracking data collected using high-speed cameras and analyzed in real time using technology developed by a British company, TennisViz, and Tennis Data Innovations (TDI), a joint venture of the ATP Tour and, ATP Media was developed.
Djokovic wasn't a completely different player in those two singles losses to Sinner, but he had figured out which parts of his game he needed to pay more attention to.
He had to be more aggressive, go on the attack and score more points where he had gained the advantage and was on the offensive – what tennis experts call his “conversion rate.” And he did it. His conversion rate in this group stage game was 61 percent, nine percentage points below his season average. In the final he increased the rate to 78 percent.
Sinner was ahead in the group game with a conversion rate of 67 percent. In the final, this value fell to 54 percent.
Djokovic had to get more involved in the fight.
A game's “steal score,” which measures how often a player wins a point after the opponent has gained an advantage, may reflect this. Djokovic's steal score in the final was 46 percent in the final, compared to 33 percent in the group stage. In contrast, Sinner's steal score plummeted, falling from 39 percent to 22 percent.
He had to serve better.
He did that too. His first service rate in the group stage was an ugly 61 percent. In the final it was 70 percent. But not only did his serve go in more, it also landed more evenly, closer to the lines. The average distance between the line and his ball in the final was 43 centimeters, compared to 54 centimeters in group play.
With Sinner pouncing more on serves aimed at the sideline or having to defend against deep serves hitting his body, Djokovic could use his dangerous forehand off serve, the so-called “plus-one” shot. A whopping 62 percent of those plus-one shots were forehand shots in the final, compared to 49 percent in the group stage. And he swung with abandon, averaging 76 mph on his forehand, compared to 71 mph five nights earlier.
How much additional damage was caused by this?
Sinner hit the same percentage of deep balls in both games, but Djokovic's increased speed and accuracy forced him into more errors. Djokovic also hit far fewer short balls for Sinner to pounce on.
Djokovic's groundstroke placement in the first game
Only 14 percent of the balls were too short in the match won by Djokovic
Djokovic said that in addition to examining what went wrong for him in the group stage, he also experienced a change in attitude between his two matches against Sinner in Turin.
His victory in his first match at the tour final against Holger Rune secured him number 1 in the world rankings at the end of the year. That was one of Djokovic's big goals for the season. Afterward, he said he was mentally “kind of half in, half out,” and that showed in how he played in that first encounter with Sinner. However, once he reached the knockout rounds, things began to take off.
There were echoes of this scenario in Australia this year. Djokovic struggled to compete in his first two matches until he found himself in trouble and had to make some clever and tiring escapes. But he has been confirmed since the third round and should face Sinner. He has never lost an Australian Open semifinal – a perfect 10-0, the same record as the tournament final.
Sinner said he was very familiar with Djokovic's record. He also learned from his defeat and beat Djokovic in the Davis Cup. He is looking forward to the next chapter even though he has never beaten Djokovic in a best-of-five sets match, the closest he came was the 2022 Wimbledon quarterfinals when he was two sets ahead before Djokovic stormed back.
“It’s going to be tough,” Sinner said. “I will control what is controllable, i.e. give 100 percent, have the right attitude and fight for every ball.” And then we will see the result. That's all I can do. It doesn’t matter who my opponent is.”
Unless, of course, that opponent is Novak Djokovic.
(Top photo: Nicolo Campo/LightRocket via Getty Images)