Friday, 3 February 2017

Trading Life of Brian

Betting Tools' Brian has written a post titled "Tennis Trading With Courtsiders Present" which is, rather unusually for a betting blog, very well written and worth a read.

Unlike most sports betting / trading bloggers, Brian lays his thoughts out clearly, and appears to have studied English past the age of 14. 

I'll let you read the post yourselves, but I wanted to discuss a couple of Brian's paragraphs. He writes: 
Well aside from the endless hours of watching tennis and being extremely patient you have to enter the market between service games or at the end of sets. You know that the sit-down period every 2 games is 90 seconds and with the overround tight at little over 100% you can’t get stung. If there are no gaps in the prices and plenty of liquidity either side you can be confident that the odds are statistically accurate otherwise one side would be picked off by someone with a more accurate model. It’s the job of liquidity providers to set the odds as accurately as possible and pick anything off either side of it.
Brian is correct that when the Back and Lay prices are separated by 0.01 point, you won't get too badly hurt, but the problem is that while your edge is only minimally negative, it is still negative, and when you factor in commission, it is significantly negative. 5% is a lot!

If the prices are 1.5 to back, 1.51 to lay, the 'true' price is somewhere around 1.505, i.e. less than 1.51 and greater than 1.5. Now unless your model is better than those in use by the court-sider syndicates, backing at 1.5 or laying at 1.51 is a long-term losing strategy. 
  
Later, Brian writes:
Does all this mean that you can’t consistently profit? No, but it makes it very difficult. As my dad used to tell me, “no matter how good you are there’ll always be someone bigger, better and stronger out there than you.” This difficulty exists in all forms of sports betting and trading though and tennis is no more difficult than any other in my opinion.
Describing the probability of overcoming court-sider syndicates as "very difficult" is one way of putting it - a little like telling your wife you're stopping for a quick half after work before arriving home by taxi at 3am - but Brian's Dad's words are always relevant when making a decision.

Think of the Apple guy and his misplaced conviction that the stock price HAD to fall. What is it about an individual that makes them think they have seen something that others, in this case full-time analysts whose job it is to analyse Apple's numbers and statements, have missed? 

Later, Brian writes:
With a lot of hard work though, it is possible to profit regularly from manual trading and I’ve seen enough evidence from my own trading and that of others to be confident about this.
This is certainly true, but no longer in sports such as tennis.  
I also think that there may be some sceptics trying too hard to prove what they believe i.e. that it isn’t possible and that there’s very much an element of curiosity with some.
Perhaps pointing out that it is illogical, and rather unlikely, to believe that you are better than all the court-siders who trade tennis for a living and are in direct competition with you, is being sceptical, but I'm certainly curious as to how anyone might seriously think that.   
As intelligent as you may be you just might not be suited to sitting watching, reading and evaluating a tennis match in play and controlling your emotions, particularly if you don’t enjoy the sport. If you do and can make it work however, it is only you who knows whether it’s worth the consistent effort.
Tennis for me is a game to be played, not watched, and the length of tennis matches is another reason why I have never got into the sport as a trader. I'm realistic to know that I will never 'evaluate' a tennis match as well as others who love the game and do this stuff every day. 

And if anyone comes along who can beat the court-sider advantage, rest assured it'll be very short-term as the court-sider models will adapt.

Brian ends with:
So, is consistently profiting from manual Tennis Trading where courtsiders exist impossible? No, but courtsiders or not, it is very difficult and for a very high percentage it’s unlikely.
On that, we can agree.  

3 comments:

  1. You speak as if you have made some money or something Cassandra. The bitterness of losing on Betfair does not show. Nor does the regular sniping at others services, how is XXDraws going by the way? Another in your catalogue of failures?

    Atlas! Despite everything being impossible in both yours and your sidekick Jim-bob the part time mature student that lives with his parents opinion. We all need to read his latest book. The "summary of a few other books" book. Hypocrisy? Maybe you could do some kind of XXDraws-Failed Algo bundle?

    Rambling on as you do. What are your thoughts on Betfair cracking down on courtsiding, wire fraud and replacing algorithms with their own? Seeing you are the know-all in all 3! Especially the betting from illegal countries part.

    Yours,
    Some other guy

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  2. Appreciate the kind words, thanks Cassini. I'd be interested to hear why you think the US sports that you used to trade so well are more difficult for you now?

    I would think that the introduction of the cross-matcher (which certainly seems to prevent selections trading as low as they used to inplay), as well as the premium charge and lower liquidity levels, have been the biggest factors but I would think that these sports could have 'courtsiders' as well?

    Apologies if you've touched on this before and I do remember you saying you have less time for trading in general.

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  3. I'm not sure I agree with you. Courtsiders are trading information flow and only need a basic model to profit. They need to know the direction price will move in and approximately where the market will settle after the news. They want to capture the bulk of the move and close out the trade immediately afterwards. They do not need to predict to the tick where the price should be afterwards as sweeping those last few ticks aren't worth the effort. As such a basic model calibrated against market prices is sufficient. Essentially the courtsiders are just reflecting the market's opinion, if the market knew all the information.

    If they have a more sophisticated model then they may end up holding positions, so they aren't "pure" courtsiders and a portion of their funds is being used speculatively. That means their model is competing against others. One can view that as their courtsiding money sweeping to the basic model (market) price, and the speculative portion as being a trade at that price.

    Either way, no matter where the market settles, it isn't necessarily at the fair price. Markets aren't perfectly efficient, I presume you'd agree otherwise you wouldn't be involved in them at all. I don't see why there shouldn't ever be moments when your model/view might not significantly disagree with the market price.

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