How the top tennis players perform on grass – A Wimbledon preview

The severe rain delays during the French Open led to a very packed match schedule in the final days of the tournament. Novak Djokovic complained about the fact that he had to play four matches in five days but still managed to put away Andy Murray in the final relatively comfortably.

With this result, the world number 1 won his second major this season in as many tries. With the third Grand Slam around the corner at Wimbledon, it’s very important for players to quickly adapt to the change in surface from clay to grass.

Grass has very different features to clay. The slippery surface creates a lower ball bounce and hence a faster game. These characteristics were reflected in the French Open Prediction preview that The Stats Zone carried out last month, where grass saw the highest proportion of service games won at 83.1%.

With this in mind, The Stats Zone has decided to delve into the data around performance on grass to better understand its implications. We will also look at the data for the top 10 players on the ATP World Tour and see where they sit in relation to each other prior to Wimbledon. This will open up an opportunity to predict who is most likely to win the third major tournament in 2016.

The data was collected on Friday June 17 from the ATP World Tour website and reflects performance statistics for the top 10 ranked players in the last 52 weeks. In order to analyse which players have performed best in this time period we have looked at the percentage of service and return games won on grass for each respective player. With the understanding that in major tournaments stress is also an influencing factor on performance, we have also decided to look at how the players perform under pressure. The ATP World Tour websites offers an ‘Under Pressure Rating’, which is calculated by adding up % break points converted, % break points saved, % tie breaks won and % of deciding sets won.

In the last stage of the analysis, we try to predict who will be the winner at Wimbledon. In order to do this we have added up the proportion of service and return games won and multiplied this by 100. This is referred to as the ‘Grass Performance Index’ and will give a score of the overall grass performance for each player. We will then compare this Performance Index with the Under Pressure Rating to see who is more likely to do well in the tournament.

The graph below illustrates the percentage of games won for each player on grass. We can see that the world number 1, Novak Djokovic, naturally is the strongest server in the field at 95.1% of his service games won. Roger Federer is second in the field at 94.4% followed by Milos Raonic at 94.3% (0.7% and 0.8% points respectively behind Djokovic). Interestingly, Rafael Nadal has the worst service % in the field at 81.6%, significantly behind all other top 10 players.

Moving on to the return performance we can see that again Djokovic scores the highest percentage at 24.2% of return games won, just ahead of Kei Nishikori and Richard Gasquet at 23.8% and 23.6% respectively. Comparing the grass return performance vs. the previous clay analysis we can see that there is less volatility on grass with 7 out of 10 players sitting within 5% of each other. This suggests that it is easier to return on clay, as we would expect, considering the speed of the surface.

The graph below looks at the Under Pressure Rating where we can see that Andy Murray is far superior to the rest of the field at 314.4. In contrast, Novak Djokovic is a remarkable 51.7 index points behind the Brit at 262.7. This suggests that Murray is very good at keeping his head cool when he’s put under pressure and fight his way back into the game. However, it could be argued that a player like Djokovic is more dominant and therefore is put under pressure less often than Murray, hence giving him a weaker Under Pressure Rating.

The final graph is the aforementioned Grass Performance Index. This index graph shows us that Djokovic scores the highest at 119.3. This is 5.1 index points ahead of Roger Federer at 114.2. Notably, this gap is larger than the difference between the subsequent six players (with a range of 4.7 index points between them). This suggests that aside from Djokovic, the top 10 players on the ATP Tour are relatively evenly matched when looking at the Grass Performance Index. It comes as no surprise that when we compare the Grass Performance Index and the Under Pressure Rating we can see that Andy Murray seems to have by far the best chance to challenge Djokovic at Wimbledon followed by Roger Federer and Kei Nishikori.

To conclude, we have looked at the key statistics for performance on grass in the run up to Wimbledon. In the data, as you would expect, it’s clear that Novak Djokovic scores the highest on the Grass Performance Index and hence is a strong tournament favorite. Andy Murray seems to be the most likely candidate to be able to challenge the world’s number one tennis player, helped by the very impressive rating for when he plays under pressure. When we further combine the Grass Performance Index and the Under Pressure Rating, two outsiders that might give “Djoko” a run for his money are the ever-strong Swiss Roger Federer and the Japanese Kei Nishikori.