First-serve performance is split into two statistical categories: first serves made and first serves won. Would joining them together as one metric provide a better understanding of how well your first serve really performed?
An Infosys ATP Insights analysis of these two statistics identifies that they tell a good story in their own right, but a richer narrative emerges once they are blended together as one. For this hypothetical situation, let’s call the new metric First-Serve Rating.
Here’s why it’s a good idea. Take for example a first-round match from this year’s Erste Bank Open in Vienna, in which Jannik Sinner defeated Casper Ruud 7-6(2), 6-3. Below are their first-serve statistics.
• First Serves Made = 56% (41/73)
• First Serves Won = 76% (31/41)
• First Serves Made = 65% (49/75)
• First Serves Won = 65% (32/49)
So whose first serve outperformed the other?
At first glance, Ruud made 65 per cent to Sinner’s 56 per cent, so it was probably the Norwegian. But the Italian won 76 per cent to 65 per cent, which now muddies the water. The truth is that their first-serve performance was almost identical. You would never know it by looking at the two statistics separately, but it’s immediately recognisable once you combine them.
Here’s how it works. You start by taking the first-serve made percentage and simply turn it into a whole number (56% to 56). You then take the first-serve won percentage and turn it into a decimal (76% to 0.76), and then multiply the two to get a number out of 100.
• 56% made / 76% won
• First-Serve Rating: 56 (made) x 0.76 (won) = 42.6
• 65% made / 65% won
• First-Serve Rating: 65 (made) x 0.65 (won) = 42.3
Sinner’s rating of 42.6 narrowly edged Ruud’s rating of 42.3. They both actually did just fine behind their first serves in this match. What’s important to note is that the rating is mutually exclusive, meaning both players can perform well at the same time.
To understand the quality of the rating, the traditional grading scale of A to F is applied below to add clarification.
First-Serve Rating: Grading Scale
When Lorenzo Sonego defeated World No. 1, Novak Djokovic 6-2, 6-1 in the Vienna quarter-finals, his First-Serve Rating was 53.6, which translates to a solid grade of A. Djokovic could only muster a grade of D with a 33.6 rating, which was tied for the lowest rating of the tournament.
Sonego First-Serve Rating
• 67% made / 80 won
• First-Serve Rating: 67 x 0.80 = 53.6
Djokovic First-Serve Rating
• 55% made / 61% won
• First-Serve Rating: 55 x 0.61 = 33.6
Simple math blends two statistics that have always lived separately and turns them into a new rating that provides greater insight into the specifics of player performance. Below is a table containing all completed matches in Vienna last week. The average First-Serve Rating was a strong B+ at 46.1, which makes sense for an indoor event at altitude.
Only one player achieved the rare A++ First-Serve Rating during the tournament: Stefanos Tsitsipas. The Greek scored a 60.7 with his first-serve performance in his opening-round three-set victory against Jan-Lennard Struff. Interestingly, Struff’s first-serve performance was rated as a 48.2, which was a solid B+ effort.
Andrey Rublev, the tournament’s winner, scored an A+ (55.8) to defeat defending champion Dominic Thiem in the quarter-finals and an A+ (55.1) in defeating Norbert Gombos in his opening-round match. Rublev added a first-serve grade of A (52.2) in defeating Lorenzo Sonego in the final.
Making first serves is always a good start. Winning the vast majority of them is even better. This hypothetical First-Serve Rating factors in both.
2020 Erste Bank: First-Serve Rating