Does good or bad form impact a player’s chance of winning a match?

Does good or bad form impact a player’s chance of winning a match?

By Dan Weston Jan 23, 2014

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Throughout their careers players will experience periods of good and bad form. This article investigates the effects of form on WTA tennis betting and considers whether or not a player’s run of good or bad form impacts their chance of winning a match?

What is form?

According to the Oxford dictionary it is “the state of a sports player or team with regard to their current standard of play”.

This is a very reasonable description – although it’s worth mentioning the difference between an individual player and a team. A team, in a sport like cricket, or football, can win a number of matches in a row without firing on all cylinders – the cricket team might have several players making centuries and then the majority of wickets being taken by two main bowlers, whilst a football team might be indebted to a goalkeeper playing superbly or their star striker converting more chances than average. However, a tennis player does not have the luxury of relying on their teammates.

My previous view on the subject of form was that it is “an expression of positive variance”. This, I felt, was particularly the case in tennis, where several key points often decide the outcome of matches, and points are frequently decided by minute margins. However, there are certain cases where players have gone through terrible runs – Arantxa Rus failed to win 18 WTA matches in a row between August 2012 and July 2013, winning just several times on the lower ITF tour during that period.

Therefore, I decided to analyse the effect of what I perceived to be good and bad form from the current WTA top 100, from January 2013 until 22nd January 2014, to see if the markets takes either into account too much, or not enough.

For the purposes of this article, I deemed the following to be indicators of good form:-

A top 5 player winning 6 or more matches in a row.

A 6-10 rank player winning 5 or more matches in a row.

An 11-20 rank player winning 4 or more matches in a row.

A 21-100 rank player winning 3 or more matches in a row (split into 21-50 and 51-100 ranking brackets).

I then deemed the following to be indicators of bad form:-

A top 5 player losing 2 or more matches in a row.

A 6-50 rank player losing 3 or more matches in a row (split into 6-10, 11-20 and 21-50 ranking brackets).

A 51-100 rank player losing 4 or more matches in a row.

Betting on WTA players in good form

To clarify further, the rank used in the sample was the rank of the player at the point of the match. Qualifying and ITF matches were counted as indicators of form, but only the results of WTA Main Tour & Federation Cup matches were included in the profit and loss statistics. I also made the decision to clear all form at the end of the season, as almost all players took at least two months off from competitive tennis. A match was deemed void should a set not be completed, and all prices used were Pinnacle Sports’ closing prices.

The following table illustrates my findings for players indicating good form, sorted by rank:-

Rank

Matches

Wins

Win%

P&L (100)

ROI

Top 5

104

93

89.42

192

1.85

6-10

17

10

58.82

-44

-2.59

11-20

51

29

56.86

1049

20.57

21-50

162

82

50.62

2341

14.45

51-100

187

80

42.78

-2941

-15.73

Overall

521

294

56.43

597

1.15

The table shows that overall there was negligible benefit backing players indicating good form on a general basis. However, it’s clear to see that the ranking bracket 51-100 had the lowest win percentage (unsurprisingly considering they are a lower calibre of player). Furthermore, and more importantly, backing these players for level 100 stakes showed a huge loss recorded, with a shocking return on investment of -15.73%.

Many of the matches sampled in this area followed a certain trend – a player would either win two qualifying matches, win their first round main draw match (often as a favourite) and then lose their second round match, or win three qualifying matches and lose their first round main draw match.

It can also be seen that backing higher ranked players in form showed strong returns. Whilst the top 5 players showed a small return, it’s not that surprising – they were often priced as very heavy favourite. The sample for players ranked 6-10 was tiny, but it was the 11-50 bracket where returns were stellar.

With the brackets combined, the players ranked 11-50 played 213 matches when in good form, winning 111 (52.11% win rate), generating profits of 3,390 from level 100 stakes – equating to a superb return on investment of 15.92%.

The next table shows the results of players in good form, when sorted by starting price: -

Price

Matches

Wins

Win%

P&L (100)

ROI

<1.20

105

98

93.33

116

1.10

1.20-1.49

72

58

80.56

530

7.36

1.50-1.99

96

65

67.71

1237

12.89

2.00-2.99

115

50

43.48

206

1.79

3.00-5.99

81

20

24.69

-640

-7.90

6.00+

52

3

5.77

-852

-16.38

Overall

521

294

56.43

597

1.15

Here we can see a clear bias towards the shorter priced players showing in good form. This is particularly the case in the 1.20-1.49 and 1.50 to 1.99 odds ranges, with both producing strong returns of investments. Combining the two brackets resulted in 123 wins from 168 matches (73.21% win rate) with profits of 1767 from a level 100 stake (return on investment of 10.52%).

Heavy underdogs showed horrific results. Just three players from 52 won when priced over 6.00, and curiously these were all against Serena Williams. Sloane Stephens beat the world number one when priced 19.27 at the Australian Open in 2013, Ana Ivanovic defeated her at this year’s Australian Open when 9.75 and in the famous Wimbledon match last year, Sabine Lisicki did so at 10.46.

Even when taking into account the huge returns from these three matches that a level stake bet at these odds produced, the odds range performed atrociously from the fairly small 52 match sample.

Having seen the effects of good form, I wanted to assess the effects of bad form.

Does the market undervalue players in bad form?

Firstly, I want to make clear that from my research, a long run of defeats similar to that endured by Rus is very rare indeed. The longest in the top 100 was eight in a row last season by several players, and that is also Caroline Garcia’s run currently. Su Wei Hsieh was an interesting player to analyse – she lost three matches in a row twice, plus four and five matches in a row once each. Therefore she won when ‘out of form’ four times, at prices of 2.19, 1.72, 3.60 and 1.65.

It would seem that the market is well aware of the fact the player is out of form and prices the player more generously than they might usually be – some examples of this I picked out from my research are the following:-

Mona Barthel started 1.61 against Vesna Dolonc having lost three matches in a row (two as favourite).

Venus Williams started 1.37 against Jana Cepelova having lost three times priced between 1.57 and 2.05.

Francesca Schiavone started 1.67 against Sharon Fichman on her favoured clay surface after five defeats in a row. Channelle Scheepers started 1.34 against Adriana Perez (world rank 263) after four defeats in a row.

We can see here that all four players started at a bigger price than would usually be expected (and all four won) against limited opponents.

It is hard to draw many conclusions from the tables below showing the results of players in bad form by rank and price range – the sample size isn’t huge.

Rank

Matches

Wins

Win%

P&L (100)

ROI

Top 5

9

5

55.56

-337

-37.44

6-10

8

6

75.00

230

28.75

11-20

6

3

50.00

-88

21-50

86

48

55.81

479

5.57

51-100

43

21

48.84

-288

-6.70

Overall

152

83

54.61

-4

-0.03

Price

Matches

Wins

Win%

P&L (100)

ROI

<1.20

11

8

72.73

-202

-18.36

1.20-1.49

34

28

82.35

352

10.35

1.50-1.99

45

25

55.56

-312

-6.93

2.00-2.99

35

16

45.71

250

7.14

3.00-5.99

21

5

23.81

-99

-4.71

6.00+

6

1

16.67

7

1.17

Overall

152

83

54.61

-4

-0.03

What may surprise many is that backing players in bad form did not generate a significant positive or negative return overall – the market overall seems to have taken this into account very well.

Having said this, it’s definitely keeping an eye on players ranked 21-50 after three defeats especially when priced in the region of 1.20 to 1.49 – from the small sample it would appear that they are priced too generously against very weak opposition.

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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