# What is the tennis dominance ratio?

In tennis, the dominance of a player is scattered across a set, a match, a tournament and the turf. The player’s victory can be analyzed based on various factors like the number of first serve points won, second serve points won, break point conversion, etc.

So how does a player get the tag of being a “dominant” one based on his performance. Most would say that a straight sets victory would be a dominant win. But what if the score line reads 7-6,7-6? The next favoured point will be of that of the total points won by the player. But then players are known to win by the Simpson’s Paradox wherein a player at the losing end has won more points than the player who won the match. The last point that can be put forth is the break point conversion of a player. Now this can be a close factor in associating a player with “dominance.”

The reason is that a player can create break point opportunities for himself on multiple occasions and has been able to read his opponent’s serve properly. But the ratio of break point conversion is a tricky one. You can create a triple break point opportunity but there are chances that your opponent forces you into a deuce, thereby regaining his confidence on his serve. Now since we are out of options in determining the prime reason for a player’s dominance, lets discuss about the Tennis Dominance Ratio (DR).

Carl Bialik, a Yalie, came up with this stat in determining a player’s dominance. The ratio is an outcome of the percentage of points that a player wins against his opponent to the percentage of points that he loses on his own serve. This ratio is a better one as it assesses a player’s game on the opponent’s serve. It also takes into consideration of a player’s performance in a game wherein he may or may not be serving. This makes a player realize that he/she needs to lay particular emphasis on understanding the importance of a love hold. It also keeps them motivated in order to stay upbeat and focused on the aim to break the opponent’s serve.

Despite being the most favoured nominee in the list of factors that determine a player’s dominance, it is not 100% correct in every match. There have been matches where a player’s DR has been better than his opponent at the end of the match and yet he is the one at the losing end. Such are the proven results of the dominance ratio, that if a player loses in a situation where he has a higher DR, he is said to have won a “Lottery match.”

Ideally, the dominance ratio of a player varies in a range between 0.67-1.5. Based on the usual ideology, a dominance ratio of 1 is considered to be a positive one. A dominance ratio higher than 1.5 is even better. For example, in 2017 at Halle, when Federer won yet another title after beating Alexander Zverev, his dominance ratio in that particular match was 2.38. The matches before the final had the following dominance ratios for Federer: 1.16,1.52,1.53,1.98. Thus, not only does the DR system analyze the dominance but it also determines by tracking the numbers as to till how long and how consistently the player is able to dominate.

The dominance ratio of the Big 3 in 2016 was:
– Novak Djokovic: 1.35

– Roger Federer: 1.33

The ratio of the same four players in 2017 was:
– Novak Djokovic: 1.20

– Roger Federer: 1.37

Not only does the DR help in comparing the dominance of players on tour but now a days betters use this as a measure to stack the odds against the players. Records can be collected and the comparison of the peak performances of two players in two different time periods can also be done by dominance ratios.
Thus, tennis dominance ratio is an important tool in measuring the dominance of a player in a match, a tournament or even the turf.