Friday, 9 October 2020

New Balls Please

I have been critical in the past about the quality of some of Pinnacle's articles which are frankly sometimes embarrassing, but an excellent article and a great example of creative thinking comes in this article about the impact of ageing balls in tennis

It's probably fortunate that author Jonathon Brycki's interest is in sports and not medicine, or the article might have been quite a distressing read for men of a certain age, but for anyone who is a tennis in-play "between games" bettor, this is a must-read article.

I say "between games" because as I have written before, court-siders will always an advantage in-play, but between games when the market has settled, an edge such as the one proposed by Jonathon might be significant. 

The data from eight years of Grand Slams indicates that ageing balls do have an affect on serve and hold percentages. The magnitude is somewhere in the order of 1-2 percentage points for both. While this may seem relatively insignificant, in betting markets that are becoming increasingly efficient, a percent or two will often be the difference between getting your money in behind and having an edge.

The margin might still be too large to overcome, as Jonathon makes clear here:

It’s unclear whether bookmaker’s live tennis models incorporate the age of the balls, and even if they don’t, the inefficiency may not be large enough to overcome their margin. In any case, incorporating potentially unique data and insights into your model will drive it in the right direction, and improve the accuracy of your predictions.

As I have mentioned before, in a binary market, grandma should be able to pick winners 50% of the time, so in a market with a tight margin, you don't need a huge advantage to be into profit.

But back to the article, and kudos to Jonathon for the idea, the research and for sharing his findings, although perhaps the fact that his findings have been shared is proof that the edge isn't of any practical use. 

Regardless, it's a great example of the process we should all be following in our never ending quest for an edge. I wonder if any such study has been done in cricket regarding the impact of an ageing ball?  

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