Does the market take surface changes into account efficiently?

Does the market take surface changes into account efficiently?

By Dan Weston May 9, 2014

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There is often much speculation as to the effect of surface change on tennis players, with the general consensus both in the media and social media being that it cannot be of any assistance to a player’s chances of winning their first match on a new surface.  This article assesses whether the tennis betting market has been efficient in the last 12 months when pricing ATP players who are playing on a new surface.

Differences in court surface

It is logical to assume that this speculation is true – when competing on two different surfaces in consecutive tournaments, a player’s chances of success are not improved.  This is because different surfaces have varying characteristics, which favour different player genres.  For example, big servers tend to thrive on hard and indoor hard courts, whereas grinders tend to favour clay courts.  There are also several players that thrive on grass – Yen-Hsun Lu and the recently retired Xavier Malisse spring to mind in the ATP, and Tamira Paszek and Tsvetana Pironkova in the WTA.

The following table illustrates the difference between the various surfaces in the ATP:-

Surface

12 Month Service Hold (Mean %)

12 Month Opponent Break (Mean %)

12 Month Aces Per Game %

12 Month Break Points Faced/Game %

Hard

79.0

21.0

0.54

0.53

Indoor Hard

80.9

19.1

0.57

0.52

Clay

75.8

24.2

0.35

0.59

Grass

82.4

17.6

0.61

0.49

As can be seen from the above table, grass and indoor hard surfaces in particular benefit players with a strong serve. The quicker conditions generally found on these surfaces lead to service holds in excess of 80%, and also the highest aces per game and lowest break points faced per game percentages.

Clay is considerably worse for service holds, with there being 6.6% fewer service breaks on that surface than on grass, and the aces per game percentage drops significantly from all other surfaces.

Clearly the evidence that the above table provides illustrates that it should be difficult for players – particularly those at the extremes of certain genres – such as John Isner, Milos Raonic and Ivo Karlovic for big servers, and the likes of Juan Monaco, Pablo Andujar and Carlos Berlocq for traditional clay courters – to adapt their game to the different characteristics of one surface when they played their previous tournament on a different one.

How court surface changes impact the players

The table below shows the results of top 50 ATP players from 1st May 2013 until 6th May 2014, when switching surfaces. To clarify, any match where a set was not completed was not included, and neither was a match where there was an injury absence between the surface changes. All prices used were Pinnacle Sports’ closing prices.

Surface Change

Matches

Wins

Win %

P/L

ROI

Hard/Indoor to Clay

50

39

78

790

15.8

Clay to Hard/Indoor

30

22

73.33

952

31.7

Clay to Grass

37

27

72.97

-71

-1.9

Grass to Clay

23

18

78.26

-256

-11.1

Grass to Hard/Indoor

24

16

66.67

32

1.3

Overall

164

122

74.39

1447

8.8

*Due to the nature of the ATP Tour calendar, no matches could be sampled when the surface changed from Hard/Indoor to Grass.

The table shows that from a sample of 164 matches, a profit of 1447 was obtained when blind backing every player in the top 50 with 100 level stakes when they changed surface. The return on investment of 8.8% is very strong for a blind-backed scenario and if this was maintained through a bigger sample, it would indicate that this would have a very large edge on the market.

It can be witnessed that despite individual surface change samples being small, it would appear that players had very little difficulties coping with the switch to hard/indoor to clay, and clay to hard/indoor. With the majority of players on tour having at least a reasonable level of competence on both hard and clay surfaces, this perhaps isn’t hugely surprising, but the large profits generated certainly are.

However, there is no doubt that the players struggled significantly when making the surface switches between clay and grass – the two surfaces with the biggest differences in characteristics. Again, this is logical, and should the figures be replicated throughout a bigger sample than the 60 combined, this would indicate opposition of players in this scenario should be strongly considered.

Assessing short-priced players with a view to opposing them during a surface change was also analysed.

When priced below 1.25, 58 players were sampled and these players won 51 times (87.9%). However, despite the high win percentage, because of the short prices involved in backing these players, a hypothetical 100 stake in this scenario resulted in a small loss of 87 (-1.5% ROI).

Certain players struggled at these short prices after switching surfaces, with none more so than David Ferrer. The world ranked 5 Spaniard, who has honed his game from being a traditional clay courter to being competent on all surfaces, was defeated by surface specialist Xavier Malisse at s-Hertogenbosch (grass) at 1.236 following his French Open final defeat to Rafael Nadal, and was also beaten by Alex Bogomolov Jr at 1.104 on hard court after his previous match was on grass at Wimbledon.

As part of a balanced betting strategy, surface changes should definitely be taken into account, and the nuances of each surface and the switches between them should be strongly considered.

Dan Weston is a freelance tennis writer who, along with producing expert content for Pinnacle Sports, also produces his own tennis rating system, and trading analysis, which can be found at www.tennisratings.co.uk.

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