Move In Or Stay Back? Depends Who You Ask!
Step into the ball. It’s been a part of tennis coaching vernacular for eons, but it is not a panacea that every player employs to win matches in the modern game.
An Infosys ATP Beyond The Numbers analysis of 67 matches on Hawk-Eye data courts at this month’s BNP Paribas Open at Indian Wells found that some players succeeded by stepping inside the baseline to hit the ball but others benefitted by staying deeper in the court.
While the macro picture was mixed, important takeaways could be found when drilling down to specific players. Case in point: Taylor Fritz, who reached his first ATP Masters 1000 semi-final in the desert by stepping forward to the ball better than any of his opponents.
Fritz: Percentage Of Shots Contacted Inside The Baseline
| Opponent | Fritz Inside | Opp. Inside |
| N. Basilashvili | 13% | 10% |
| A. Zverev | 31% | 17% |
| J. Sinner | 21% | 15% |
| M. Berrettini | 45% | 30% |
| B. Nakashima | 34% | 26% |
| AVERAGE | 29% | 20% |
Fritz made contact with the ball 29 per cent of the time inside the baseline on average, compared to just 20 per cent for his five opponents. His two top 10 victories against No. 4, Alexander Zverev, and No. 7, Matteo Berrettini, were built on stepping forward to attack the ball much more than his higher-ranked opponents. Fritz made contact with the ball 45 per cent of the time inside the baseline against Berrettini and 31 per cent against Zverev. Fritz was well rewarded for taking the ball early and dictating play.
Tellingly, in the match he lost, Fritz contacted the ball just 13 per cent of the time as the power of Nikoloz Basilashvili kept him pinned behind the baseline. That was massively down on his tournament match average of 29 per cent.
Stepping into the ball involves a number of factors, including hitting a deep or forceful shot on the previous ball to elicit a short ball to move forward against. It is also about having the desire and skillset to take the ball on the rise or at the top of the bounce to open up angles of the court and rush the opponent’s preparation for the next shot.
When Fritz defeated Zverev, the German only made contact with his forehand 19 per cent of the time inside the baseline. But Zverev also featured as the leader in the data set with forehands struck inside the baseline, hitting an astounding 51 per cent inside the baseline in his 6-1, 6-3 round of 16 victory against Gael Monfils.
But there are two sides to this coin. Players were also able to succeed by staying back deep in the court.
The three zones of court position are:
Zone 1. Inside the baseline
Zone 2. Within two metres behind the baseline
Zone 3. Past two metres behind the baseline
Basilashvili thrived in the very deep zone, farther back than two metres behind the baseline, to reach the final.
Basilashvili: Percentage Of Shots In The Three Zones
| Opponent | Zone 1 | Zone 2 | Zone 3 |
| C. Norrie | 13% | 57% | 30% |
| T. Fritz | 10% | 47% | 43% |
| S. Tsitsipas | 11% | 47% | 42% |
| K. Khachanov | 15% | 42% | 43% |
| A. Ramos-Vinolas | 17% | 41% | 42% |
| C. Eubanks | 9% | 37% | 54% |
| AVERAGE | 13% | 45% | 42% |
Of the seven matches for the tournament where the player won the match but stepped inside the baseline the least, Basilashvili accounted for four of them.
Basilashvili’s highest-ranked opponent he defeated was No. 3, Stefanos Tsitsipas. The ability to keep the Greek from stepping into the court like he did in previous rounds was a key component of the upset victory.
Stefanos Tsitsipas: Percentage Of Shots In The Three Zones
| Opponent | Zone 1 | Zone 2 | Zone 3 |
| N. Basilashvili | 5% | 53% | 42% |
| A. De Minaur | 25% | 57% | 18% |
| F. Fognini | 22% | 59% | 19% |
| P. Martinez | 35% | 42% | 23% |
| AVERAGE | 22% | 53% | 26% |
Tsitsipas contacted the ball on average 27 per cent of the time in his first three matches at Indian Wells, with the standout being 35 per cent in his round of 64 match against Pedro Martinez. But in his loss to Basilashvili, Tsitsipas only made contact with the ball 5 per cent of the time inside the baseline.
That was the smallest amount struck inside the baseline by any player in the tournament. Overall, players were more likely to step inside the baseline to make contact with a forehand over a backhand.
2021 BNP Paribas Open: Forehands v Backhands Contact Points
| Match | Zone 1 | Zone 2 | Zone 3 |
| Forehands | 26% | 50% | 24% |
| Backhands | 24% | 53% | 23% |
In general, stepping into the ball and making contact inside the baseline correlated more with winning the match than staying deep behind the baseline. But it’s not a fix-all for all players, as there were still many matches won where the match winner was not the player with the highest percentage of shots inside the baseline.
This metric is best used in a match-by-match comparison, factoring in specific head-to-head playing styles. Horses for courses in the California desert.