Coaches have for years drilled into budding tennis players and professionals that serving to the backhand provides a stronger chance of winning second-serve points. In fact, it is clear that this tactic is the norm on the ATP Tour. Fifty per cent of serves have been directed to the backhand corner and 35 per cent to the body – mainly to the backhand side – leaving only 15 per cent of serves delivered to the forehand.

The thinking is simple: Serving to the backhand provides a safer option when sending down a slower delivery on the second serve. Naturally, forehand returns are more dangerous, so a high ball to the backhand provides a better chance of neutralising the opponent’s return, while reducing the risk of double faulting.

Animation 1: Serve Zone Trajectories on second serves to Deuce court: Win % and In %

However, the growth of increasingly sophisticated data and analysis of each and every action in the sport of tennis undermines the logic behind this long-held belief.

ATP players win 51 per cent of points when serving to the forehand corner versus just 49 per cent when serving to the backhand corner.

In other words, primarily directing the second serve to the backhand of an ATP opponent typically reduces the chances of winning the point. This information is derived from detailed analysis for nearly 150 right-handed ATP players with at least 1,000 second serves to right-handed opponents over a 10-year period.

Table 1: High frequency and second-serve win per centage to forehand and backhand corners of 150 right-handed ATP players with at least 1,000 second serves to right-handed opponents over a 10-year period.

What’s more, well-placed deuce-side second serves to the forehand corner generate 8.5 per cent more points won than well-placed serves to the backhand corner of the same service box. Perhaps even more surprisingly, second serves to the forehand corner in the deuce court lead to eight per cent more unreturned serves and lead servers to win 17 per cent more deuce-side return points in shorter rallies of five or fewer shots.

Animation 2: Win % heatmap for placement of second serves to Deuce court

All of this goes to highlight the growing importance of accessing and understanding detailed data analysis on Tour to enable players to leverage every marginal gain available to them. This is why Tennis Data Innovations is committed to delivering detailed tracking data on every court across the ATP Tour in 2023, to shed light on the most effective tactics and strategies in tennis.

And what does all this mean in practice? Well, just as we have seen with the inexorable rise of three-pointers in the NBA driven by crunching the data, so we are seeing the second serve to the forehand rise, increasing from 15 per cent in 2012 to 22 per cent in 2022 (a 47 per cent jump).

Novak Djokovic and Daniil Medvedev are two players who have embraced data analysis and who often serve to the forehand on their second serve on both sides of the court with success.

However, other players have been slower to embrace the insights provided by data analytics and we see a number who rarely serve to the forehand. Not surprisingly, they are missing out on crucial points.

Grigor Dimitrov, as an example, may have gained a significant number of points by serving to the forehand corner 25 per cent of the time instead of 10 per cent. The five per cent differential gained on those second serves could have led to several additional matches being won in the course of a season, such are the fine margins in our sport.

In real terms, the difference in Pepperstone ATP Rankings points and prize money foregone by an over-reliance on serving to the backhand could be sizeable.

Table 2: Low frequency and second-serve win percentage to forehand and backhand corners. Date set of 150 right-handed ATP players with at least 1,000 second serves to right-handed opponents over a 10-year period.

Of course, we should not assume that pushing more second serves to the forehand will automatically increase the win per centage on all of those points. There is undoubtedly an element of surprise with serves to the forehand side currently that underpins its statistical advantage – built on the ingrained expectation of more serves being delivered to the other corner. This raises the question of how much more ATP players should serve to the forehand on second serve? Most players would benefit significantly if they served to the forehand at least 15-20 per cent more than they currently do.

One reason that second serves to the forehand have such a high win per centage is that they are surprising to the returner. Of course, as the per centage of serves by a player to the forehand increases, the win per centage decreases. Our analysis shows that increasing the proportion of serves to the forehand does not decrease the per centage of points won by very much. And more variation in second-serve location will deliver an increase in the win per centage of serves that continue to go to the backhand.

Given ever-improving racquets, string, and training technologies, which lead to faster and more accurate serves, we believe the per centage of serves to the forehand on second serve will continue to rise, with the expectation that one day we will see something closer to parity between the two sides.

Until then, we’ll likely continue to see an enlightened group of players and coaches take advantage of these marginal gains. In isolation, they may not seem like much, but in a sport where winning 51 per cent of the points will generally win you the match, these fine margins can be what separates success from failure.

Editor’s Note: This is the first in a three-part series in which Golden Set Analytics and TDI are looking at the increasing prominence and importance of deeper tennis data in helping us all better understand the dynamics of the sport, whether as players, coaches, fans or administrators.