Johanna Konta, Simona Halep and Meaningless Data

A couple of areas caught my interest in the last week, so I thought I'd blog with my thoughts on them.

To start with, I want to look at several screenshots that I saved from the BBC Sport website.  The first, shown below, makes two statements that I want to comment on...


The first statement that I want to assess is 'Konta leads 1-0 in head-to-head' - this has to rank up there with the most meaningless stat that I have ever seen.  It's basically just a page-filler, and lazy journalism.  However, by the sheer fact that BBC Sport have deigned to include it in their summary, people will be misled and think that it is relevant to this match.

From my research, a three-match head to head lead, ideally on similar surfaces to a current match-up, with players at a similar current level to those previous matches, was required for a head to head stat to have any relevance whatsoever.

With that cleared up, we can look at the second statement - 'Jo Konta has a word with her coach Wim Fissette at the end of the first set.  Whatever he has said has worked... Konta races into a 0-40 lead in Wozniacki's opening service game.'

How do we know that what Fissette has said has had any impact on the upcoming game in the match?  We don't.  

Konta getting to 0-40 could be down to more things than I can possibly list on here.  Fissette could well be a tactical genius, but if we are basing his level on the input that most WTA coaches give during the coaching breaks, he's probably not.  Subjective, biased, journalistic hyperbole is again misleading those who read the live reporting in this match.

Staying with BBC Sport and Johanna Konta, this second screenshot caught my attention.


Konta here is quoted as saying 'I'd like to be the best player in the world but there's a lot of work to be done between now and then.  

Actually, looking at 12 month all-surface hold/break data - an example of meaningful data - Konta isn't that far off at all, particularly when we consider the leading player, statistically, Serena Williams, is injury prone and in decline:-

Player

Rank

12 Month Hold %

12 Month Break %

Combined %






Serena Williams

2

84.4

38.0

122.4

Simona Halep

5

70.2

47.8

118.0

Johanna Konta

7

78.8

38.2

117.0

Agnieszka Radwanska

8

68.2

47.9

116.1

Karolina Pliskova

3

76.3

38.2

114.5

Angelique Kerber

1

70.5

42.0

112.5

Garbine Muguruza

6

71.9

39.5

111.4

Svetlana Kuznetsova

9

69.1

41.4

110.5

Venus Williams

10

67.8

40.1

107.9

Dominika Cibulkova

4

66.1

41.8

107.9


While a hold/break percentage below 120% isn't usually good enough to be number one on either the ATP or WTA Tour, the lack of strength in depth of the WTA Tour currently may well provide an opportunity for Konta to join Angelique Kerber in becoming a below elite level number one.  

On the subject of Kerber, I notice quite a few people in the media and social media are questioning her level.  Statistically, she hasn't dropped a vast amount.  Her failure to get to the business end of events regularly is simply the mean reversion that we see in sport all the time.  

Finally, I replied to a tweet on Twitter last week, shown below:-


A 34 match unbeaten run when she has taken the first set sounds impressive for the 5th ranked player in the world, but as I wrote on Twitter, it is important to have context here.

This particular match against Konta was the only match in this run where Halep was the pre-match underdog (she closed at 2.20 on Pinnacle) and was the only time that Halep's starting price was in excess of 1.60.  

Running some numbers (and taking into account that Halep's run was actually 36 matches after winning the opening set!), the odds of her winning each match - assuming she won the first set, and adjusting the starting price to the likely level following the first set victory - the chances of this unbeaten run was 7.75%, or in decimal odds, 12.91.  

This added context turns Halep's run from being 'amazing' to merely very good, or impressive.  Many top 10 players have had similar runs in the past, and there will be plenty who will do so again in the future.



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