Monday, 24 July 2017

Men Slams Redux

A fair portion of my weekend was spent revisiting the Tennis Spreadsheet, removing matches where there was either a Walkover or a retirement prior to the completion of the first set. 

For the men in Grand Slam (Singles) events, my suggestion that:

if you're betting on Men, stick to the favourites in Australia and France, and take the rest of the year off
still holds. 

Since 2013, the outcome of backing the Pinnacle favourite at these ten events is:
More selective price shoppers could theoretically have increased their ROIs by up to 4.5% and 5.6% respectively. 

For most of us, placing ~125 bets per Slam would be a daunting task, but betting on semi-finals (favourite) and finals (underdog) only across all Grand Slams is much more rewarding in terms of ROI, up between 10.90 points to 12.60 points from the 57 matches since 2013.

Women up next, as time permits. 

Friday, 21 July 2017

Bastad Walkovers and Retirements

Don Pablo asked:

Is this article based on the analysis of singles matches only or both singles, doubles and mixed doubles matches. Clarification will be much appreciated
I didn't realise anyone bet on doubles matches, and I don't know where historical odds for these matches could be found anyway, so to clarify the results are for Singles matches only.

Brian of Betting Tools fame and fortune helped out with the walkover question writing:
Yes most require the 1st set to be completed, others the full match. When I checked at the start of the year there were 2 'first ball served' bookies who would pay out if the match had started but just checked and they both now require the first set to be completed. As far as I know there isn't anyone who pays out for a walkover.
This post on his website gives more details on rules by bookmaker, but as Brian mentions above, rules can change so don't rely on this.

Next time I have a week to spare, I'll run the numbers again excluding Walkovers and First Set retirements. 

Unfortunately, with more than half of the retirements / walkovers favouring the underdog, (for 2015 and 2016), this system isn't as good as it might have first appeared. 

Losing the likes of 14.8 and 13.0 winners (Rome and Bastad 2015) and a green system can soon go red. 

Bastad indeed!

Dogs on Tour

I mentioned yesterday that:

...if the Women's game is your preference, stick to underdogs from the fourth round onwards.
I decided that it might be worth taking a look at how this strategy has played out this season across all tournaments on the Sony Ericsson WTA Women's Tour. 

The Fourth Round in Grand Slams is the Round of 16, or Eighth-final, for non-slam events, and after 34 total tournaments, backing the underdog would have returned a profit of between 25.32 and 36.16 points from 501 bets, and ROI in the 5% to 7.2% range. 

On the face of it, not bad, but when we consider the returns from Grand Slams alone I mentioned yesterday, it's clear that this is a losing strategy across the 31 non-slam events.

I did learn something through this little exercise, which is that the Women have three tiers of event - Grand Slam, Premier and International, and in the 19 International Tournaments so far, this strategy is up between 27.34 and 34.37 points. 

Incidentally, on Hard surface tournaments, the strategy is up between 46.66 and 53.11 points most of that on Outdoor courts.

So far so good, but the season is 60 tournaments long, so I went back to 2016. Backing the underdog in the later rounds (Round of 16 to Final) would have won between 47.50 and 74.52 points from 876 bets, a similar ROI to that so far in 2017.

2015?, I hear you ask. It just keeps getting better. Only 59 tournaments that year, but the strategy is up between 60.71 and 85.93 points from 837 bets, an even higher ROI than 2016 and 2017.

So from 2015 to date, backing underdogs in the last 16 or later in every WTA event would have won between 133.53 and 196.61 points from 2,214 bets, an ROI of between 6% and 8.9%

This is in no way a criticism of them, you can't beat free and they are very useful, but be careful if you decide to use the Tennis-Data.co.uk spreadsheets yourself, as there are several errors in them. Typically the Maximum isn't the maximum, and other times the favourite and underdog are incorrect, but a simple validation will catch these and manually correcting them isn't difficult.

I've also noticed that while there are not hat many, walkovers are included in the sheets which I should probably adjust for. Perhaps someone more familiar with tennis betting than myself can confirm that books generally only pay out on completion of the first set.  

Thursday, 20 July 2017

Wimbledon Favourites (W) Buck the Trend

Following on naturally from my previous post, for the Ladies Singles, Wimbledon 2017 was a different story where backing the favourite in every game was a very profitable strategy, up 13.40 points, an ROI of 11%.

Here are the results for backing Ladies Grand Slam favourites this year at Pinnacle's prices:

Not that I am complaining, but I did find a couple of errors in Joseph Buchdahl's Mens Wimbledon 2016 data.

In the Final, I'm pretty sure that Andy Murray was not a best priced 4.36 to win, and similarly I don't think Grigor Dimitrov was a 1.75 favourite with Pinnacle to beat Stevie Johnson in their 3rd Round match.

The previous post has been updated to correct this palpable error.

I'll update the numbers after the US Open completes the 2017 Grand Slam season, but it's clear that since 2013, if you're betting on Men, stick to the favourites in Australia and France, and take the rest of the year off, and if the Women's game is your preference, stick to underdogs from the fourth round onwards. 

Such a strategy would have profited between 34.11 and 58.47 points (Men) and between 37.10 and 53.75 points (Women). 

Not a great return for the effort involved on the men's side, and frankly not my cup of tea, but for the women, 15 matches a tournament is a manageable number of bets, and since 2013 (19 tournaments) would have an ROI of between 13% and 18.9% (37.10 to 53.75 points).

Wednesday, 19 July 2017

Favourites (M) Slammed

Wimbledon 2017 ended a run of six Men's Grand Slam tournaments where backing the favourite in every game was a profitable strategy.

Here are the results for backing Grand Slam favourites this year at Pinnacle's prices:

and for the 2016 season:
Conventional wisdom for tennis betting is that in line with the favourite-longshot bias, backing the favourite will result in you losing your money slower than you would by backing the outsider. 

Backing the outsider would have been profitable in Australia this year, simply because of two long-priced winners - Istomin beat Djokovic at a best priced 41.0 and Zverev beat Murray at a top price of 28.0.  

In the eleven Grand Slams (Men) since 2015, an underdog backer at Pinnacle's prices would have lost 181.22 points, 16.47 per tournament, while a favourite backer would be up 14.24 points, 1.29 per tournament.

If you believe in unicorns, Santa Claus, angels or gods, then by backing at the best priced books, your losses would be reduced to 108.02 points on underdogs, and profits boosted to 35.24 points on the favourites.  

Tuesday, 18 July 2017

Patsies and Strumpets

Eggmund, possibly not his real name, commented on my Physics Presumptions post:

Hello, nice blog.
I used some of the principles of Statistical Mechanics that I picked up from my Physics degree when writing my Cricket model. It could be that this is the sort of thing referred to as "Physics Presumptions".
A very charitable explanation, and one that in my opinion, isn't supported by the evidence when you consider the individual's writing in more detail. 

Here's his Pinned Tweet:
It's hard to view this nonsense as the product of an educated mind, from an individual who might be into "particle physics" or "Statistical Mechanics". 

To me, it's a nonsensical rambling with the end goal of selling a worthless tipster service to gullible individuals by adding faux intellectual gravitas to the subject. 

Eggmund, (if there was never a King Eggmund** back in the day, there should have been), is clearly a much nicer and more intelligent person than myself, and he continues: 
By the way, I like your principle of Bet-And-Forget. It nicely expressed what I've been looking for for a while as gambling time competes with family time! I'm now working on how I can build positions purely during intervals in test matches, without having to follow games live. Thank you for the tip.
The only person who benefits from betting in-play these days is someone trading the game with the advantage of being court-side / green-side / pitch-side / table-side / etc. If you do not have this edge, and most of us don't, Bet-and-Forget is the only strategy that makes any sense.

It's gratifying to see that this message is finally getting through. Trading sports sounds dangerously simple, an easy way to riches, and back in the early days of the concept it was quite possible to find a trading edge, but the markets have evolved.

One more time - If you are trading in-play, you are competing against others with more information than yourself.

Here are my thoughts from a few weeks back:
You are not going to obtain any information from your TV that hasn't already been seen, evaluated, and acted upon, by others before you.
If you, and I think quite logically you can, assume that these full-timers are not donating their money to the market each day, i.e. they are net winners, how can you, sitting at home, seriously think that you can overcome this disadvantage over the long-term and make a profit?

It's a zero sum game, and as the Warren Buffett quote from yesterday puts it:
"If you've been playing poker for half an hour and you still don't know who the patsy is, you're the patsy."
No guide in the world is going to be able to help you overcome this disadvantage. You are always working with stale information, which would be a level playing field if everyone else was too, but you're competing in markets where others have more current information than you.

It's frankly delusional to think you can be competitive under such conditions.
** I checked - no Eggmund, but we did have a couple of Edmunds and an Eadwig (955 - 959) with an interesting background:
The eldest son of Edmund I, Eadwig was about 16 when he was crowned king at Kingston-upon-Thames in southeast London. Legend has it that his coronation had to be delayed to allow Bishop Dunstan to prise Eadwig from his bed, and from between the arms of his “strumpet” and the strumpets’ mother. Perhaps unimpressed by the interruption, Eadwig had Dunstan exiled to France. Eadwig died in Gloucester when he was just 20, the circumstances of his death are not recorded.

Saturday, 15 July 2017

Physics Presumptions

There are worse ways of passing a Saturday night than doing research on behalf of @Statsbet, who prompted me to compare the League 2 Away returns discussed here, only using the Pinnacle odds scraped several hours prior to kick-off rather than the Pinnacle Closing Prices.

For the five seasons where the data is available, the results are as above. Closing prices beat the earlier prices (let's be clear that these are not "opening" prices), but over the past two seasons betting earlier has been the optimal strategy, possibly because someone revealed this simple system and the money consequently floods in towards kick-off, driving the price down. Or possibly not.

If you follow @Statsbet on Twitter, you'll find that he crosses paths and swords with some strange characters out there. 

One such individual is setting up a tipping service for next season, the cost:
Will be £50 per Calendar month for model data covering 6 leagues this season. Only accepting 10 clients to begin.
Only £50 a month! This sounded like a bargain, except that no verifiable results are to be found, and when asked how publicly available data could provide him an edge, the response was a nonsensical:
My interest was short-lived. If anyone knows what "physics presumptions" means, please let me know. My money, and I hope all of yours, shall also remain private. 
Call me old fashioned, but when someone admits to having no money, and is looking at betting on in-play football in China, it sends a message of cluelessnes and desperation rather than one of success. A few minutes later:
Imagine my surprise.

Closing Lines

Rodolfo commented: 

In recent weeks Joseph Buchdahl has published several articles on the importance of beating the closing odds. Do you consider beating the closing odds as an important factor whether particular betting strategy is profitable or not? Have you ever recorded closing odds yourself on a regular basis?
Long-time readers of this blog will know that I am a firm believer in the importance of beating the closing odds, which is why I became so excited when Joseph added Pinnacle's Closing Prices to his football sheets dating back to the 2012-13 football season.

As Joseph explains:
Closing odds reflect the largest amount of information about matches, and the maximum number of opinions being expressed through wagering on that information, and hence are most likely to be the most efficient.
As a part-timer, I have never had the time to record closing odds myself, but fortunately for all of us, Joseph has now filled the gaping hole in this area. 
Readers will know that one of my favourite sports for betting is baseball, and several years ago saw this quote on a forum discussion about closing prices:
In all free markets - pricing efficiency is generally enhanced with the addition of market participants and incremental information over time. The MLB wagering market is no exception. The closing line is generally a sharper number than the opening line. The fact that a winning MLB handicapper beats the closer more often than not is not the reason he's a winning handicapper but rather a reflection of his being a winning handicapper. He has the ability to identify the smart side of the early (weaker) number. More often than not, his good judgment will be confirmed by the subsequent line movement. His early wager will thus, more often than not, have a value edge vis a vis the ultimate closing number. It's as simple as that.
Anyone who is profitable in MLB over more than a half season without beating the closing price more often than not - who thinks he is good - is mistaking good luck for good play. And to any of you who believe that beating the closer is a meaningless or overrated measure of a good handicapper - I can only say you are wrong - and assure you that the Las Vegas books would agree with me.
So the importance of beating the closing line has been clear to me for several years and is why my MLB, NFL, NBA systems etc. all use the closing prices. In reality of course, it's impractical to place all bets at these closing prices, (sometimes you'll get lucky, other times not so lucky) but it's always the benchmark to be used when evaluating a system. It also allows others to easily verify the results. 

One of the many problems with measuring a football tipster's edge is that the prices they claim are often, to put it favourably, somewhat arbitrary. Prices move throughout the days leading up to a match, reacting to new information and money coming in to the markets. This allows someone to cherry pick the prices they record their results against. 

It is why my own selections and results were recorded using Pinnacle's prices wherever possible. This consistency and transparency was a welcome improvement to the opaqueness of others, but three seasons ago, was still less than perfect. 

Prices were scraped, at best several hours, and at worst, several days before kick-off, thus the role of luck played a bigger part than it should - for example, the late news that a star player would miss the game wasn't reflected in the odds used. The most extreme example is the scraping of a price on a Friday afternoon for a game on Monday night. Clearly less than ideal.

The long overdue addition of Closing Prices for football means that everyone now has a standard to measure their performance against. Be wary of anyone who doesn't report their results against this benchmark. 

A Closing Line for the Over / Under markets would be a nice addition too if Joseph is reading this.

Finally, Football Investor Stewboss clarified things, writing:
Sorry if I got the wrong end of the stick re your draws betting. Perhaps you should have replied to my last tweet
With everything else that's going on in my life right now, correcting a minor misunderstanding by one person on Twitter wasn't particularly high on my list of priorities. It became more important when repeated in a comment, but we're all on the same page now.

Friday, 14 July 2017

A Slightly Better Bettor

Stewboss commented on the Filter Bursting post with:

"Secrets are secrets. An edge shared is still an edge halved. If I give or sell you a secret then it's no longer a secret."

That would be true if indeed you were placing the bets yourself but as you've already informed me that you haven't I don't see why you're so keen to keep it a secret. I'm not that bothered personally as I have created my own version with slightly better results than yours :-)

Maybe you could introduce an paywall version of your blog for those in the know so to speak !!
I'm not quite sure where Stewboss got the idea from that I wasn't using this system myself. 

In response to Stewboss's initial enquiry about my Draws, I did say that I hadn't updated my own ratings in almost two years.

This was a very time consuming activity whose rewards were not justifying the additional time over a more basic single filter system.

With regard to the less time consuming Draw system, I stated that "it was a loser last season anyway!", but unfortunately for my wallet, that didn't mean that I hadn't followed the system.

Anyway, a minor misunderstanding, and good for Stewboss that he has a Draw System with improved results over mine, although some clarification on 'slightly better' is needed.

Are we talking ROI% or points?

Looking at the past five EPL seasons (i.e. those where the Pinnacle Closing Price is available), the highest ROI for backing the draw with one filter is 150.4%. Unfortunately this was from just seven selections, which across five seasons isn't too useful.

In terms of points, the best single filter for backing the draw returns a profit of 82.65 points (from 710 bets), while the best ROI from a filter generating an average of at least one bet per round (i.e. 38+ a season) is 21.5%, from 294 selections.

Filter Bursting

Jameson wasn't the first to ask:

hi. what is the second filter you applied for draws? 1st is ip 25+, and second?
Unfortunately, as I told Stewboss, since this filter has added value in each of the five EPL seasons for which we have Pinnacle Closing price data available, the filter will remain proprietary. A great man once told me:
Secrets are secrets. An edge shared is still an edge halved. If I give or sell you a secret then it's no longer a secret.
How valuable is such a 'secret' though? 

Some of you undoubtedly noticed that the number of Draws in last season's Serie A was the lowest since 1995-96. Of the 50 top flight seasons in England, France, Germany, Italy and Spain during the last ten years, only four have been lower, and two of those were in the traditionally higher scoring Bundesliga where you'd expect fewer draws. 
Unsurprisingly backing the Draw in every Serie A match last season would have been costly as usual, but the benchmark (matches where the Draw probability is 0.25 or greater) would have again been improved by applying the filter, reducing a loss of 35.01 points to a loss of just 8.99 points. 
It was the same story across Europe last season, with the filter adding a total of 133.54 points to the benchmark:
An ROI% of -1.61% isn't usually something that sets the pulse racing, but it's a whole lot better than the -12.37% on the benchmark.

One swallow doesn't make a season though, and one season doesn't make a golden goose, so I looked back a couple more seasons to see if the pattern held. 
As you can see, it did, turning a benchmark loss of nearly 150 points into a profit of over 100 points. 

For the five seasons for which we have Pinnacle's Closing prices, the results are here sorted by league / season Draw percentage:
While the correlation between the Draw and returns is obvious, the (usually) added value of the filter isn't apparently influenced by the Draw percentage.