How important is it to win the first point?

If you have listened to any of the commentary during Australian Open 2016, you have likely heard about the importance of winning the first point in a game. Of course, the commentators are right that taking a lead in a game gives a player an advantage, in the same way that taking a step closer to the finish line is always better than taking a step back. But why so much attention to the first point?

There is a general belief in tennis that a lead gives a player added confidence that can help to raise their game – a momentum effect. So, in the mind of many commentators, the sooner a player can get ahead in the game, the better.

But how much of an advantage is there to winning the first point in a game? And how much of this advantage can be attributed to momentum, where players raise their game when they are in a winning position?

To gain some insight into these questions, the data analytics team at Tennis Australia looked at the importance of the first point in the past three years of Grand Slam matches for the quarterfinalists of this year’s Australian Open. To measure importance, we calculated the advantage of winning a game when a player won the first point of the game versus having lost the first point.

First-point importance for men

Among the men who made the quarters of the AO 2016, the size of the advantage associated with the first point varied quite a lot. Spain’s No.8 seed David Ferrer has historically benefited the most from an early lead. The difference in Ferrer’s likelihood of winning a game when he takes the first point on serve compared to when he loses the first point is a whopping 32 per cent! For the remaining quarterfinalists, the advantage was between 13 per cent and 24 per cent.

An interesting trend revealed in the table below is the tendency for the players with stronger serves to have lower first-point advantages (e.g. Novak Djokovic and Roger Federer), which could be explained by the fact that a player with a better serve has a better chance of making up for any single point lost on serve.

Although the focus of commentary about the advantage of the first point is often on serve, we found that the advantage of winning the first point on return has a stronger association with winning the game than it does on serve. The average first-point advantage on return was 29 per cent compared to an average of 20 per cent on serve. There might be some concern that this difference is owing to the fact that an early lead in a return game is more common when facing weaker opponents. However, we controlled for this by using an equal number of games (return or serve) from each Grand Slam match in which a player did and did not win the first point.

What about momentum?

The advantage of the first point is a combination of the strategic advantage of having a lead in the game and the possible added boost in performance that comes with the momentum of being ahead in the game. To determine what amount of a player’s first-point advantage is owed to momentum, the data analytics team estimated the advantage that a player would be expected to have in the absence of momentum, which is when a player’s chance of winning a point on serve (or return) is the same for every point. In other words, given Djokovic wins 71 per cent of points on serve, in the absence of momentum, he would be expected to serve with a 71 per cent win probability for every point in a service game.

Momentum accounts for a small percentage of the first point advantage on serve among the Open quarterfinalists. In fact, no evidence of momentum with the first point lead was found for three of the top players: Kei Nishikori, Andy Murray, and Novak Djokovic. David Ferrer had the strongest evidence of momentum on his service game, closing out games 29 per cent more than expected when he takes the first point. Ferrer is known for his determination to win every point and this suggests that he is even more determined to win when ahead on serve.

Momentum effects were more consistent on the return game as every quarterfinalist had some evidence of raising their game on the return after winning the first point. The added confidence of an early lead was particularly important for 13^th seed Milos Raonic, where a momentum effect accounted for 26 per cent of his first point advantage on return.

First-point importance for women

Though we found a large first point advantage among the women’s quarterfinalists, the advantage on serve and return was slightly closer than for the men–22 per cent on server and 28 per cent on serve—which could be explained by the lower serve win percentage on the women’s tour.

The player who was found to have the largest advantage on serve and one of the largest on return was Angelique Kerber, who was the only player with advantages of 30 per cent or more on both sides of her game. Interestingly, world No. 1 Serena Williams, like the No. 1 male Novak Djokovic, had some of the lowest first point advantages, suggesting that Williams can comeback more easily from an early point down than other players.

* insufficient data at Grand Slam level

What about momentum?

When we looked at the role of momentum in the first-point advantage among the women’s quarterfinalists, we found that the majority of the women had no evidence of gains in performance with securing the first point in a game. Kerber was exceptional, as she was the only player who appeared to be influenced by momentum with an early lead on service and return games.

* insufficient data at Grand Slam level

Takeaways

Winning the first point in a game puts all players in a winning position, but the advantage is smallest for the strongest players who are the most capable of making up for points lost early in a game. Though it is often assumed that the main advantage of an early lead in a game is the additional confidence it gives players, the role of momentum in first point advantage is small for most players and usually absent for the best players, suggesting that the best players believe in their ability to win no matter who wins the first point.