Creating a Digital Certificate for Betfair Login

During the writing of my book Programming for Betfair I tried to make things as simple as possible out of respect for newcomers to programming. I utilised the standard login procedure for Betfair, consisting of a username/password pair. However, when programming a new algorithmic trading platform for Betfair the most annoying aspect of the process is having to log into the servers every time you test the software. During the course of a day that is a lot of logging in, especially if you use two-factor authentication.

I have been requested by a reader to provide a tutorial for authentication with a digital certificate and so I have written this article. The process was a lot easier than I had imagined. For readers of my book I also provide code which replaces the LoginForm.

Firstly, I shall point out that the certificate that you will create will be self-signed so don't imagine that you are now a certification authority and can start handing out certificates to anyone. The certificates on your browser, which authenticate websites to you, are signed by trusted third-parties. These third-parties have gone through rigorous procedures to permit their certificates to be installed inside your browser. Your certificate will be self-signed and used only for authenticating your application to Betfair and nothing else.

Betfair trusts you to sign your own certificate for your own account and no more. It is up to the user of the certificate to ensure that their security had not been compromised. That means if your account has been broken into because you have allowed someone to gain access to your private key then you are at fault and not Betfair.

The Process of Creating a Self-Signed Digital Certificate

These instructions are for Windows users. If you use another operating system then it is up to you to decipher these instructions. I cannot provide any help with that.

1) Download the OpenSSL package from Shining Light Productions. Choose the topmost Win32 OpenSSL v*.*.* Light version of the software. I have a 64-bit operating system and running the 32-bit version of the software is not going to make any difference. OpenSSL provides all the tools for creating your own certificates.

2) After downloading the package (and virus checking it) install the application, as the installer suggests, at the root of your C: drive. If asked where to copy the OpenSSL DLLs then make sure they go into the Windows system directory. The final dialog of the installer asks if you want to make a donation. If you want to then do so but if you don't then make sure you untick the check box before clicking the Finish button otherwise you will be frog-marched off to the donation site. OpenSSL is now installed.

3) Click on your Windows menu and then right-click on Computer so that you can choose its Properties. You will then see a dialog, click on Advanced system settings on the left-hand side and the following dialog will be displayed. Click the Environment Variables button.

4) In the next dialog click on the New button in the System variables section, as in the following picture. Add the variable name OPENSSL_CONF, variable value C:\OpenSSL-Win32\bin\openssl.cfg and click the OK button. OpenSSL is now fully configured. If you use a different operating system to Windows 7 then consult Google.

5) Copy an updated openssl.cfg file from this link 

and replace the existing file in the C:\OpenSSL-Win32\bin directory. This new file commands OpenSSL to create a client side certificate rather than a server side certificate.

6) Now download this batch file

that I have created and which will automatically create a self-signed digital certificate for you. Once downloaded right-click the file and run it as an administrator. You won't be able to create a certificate unless you are doing so as an adminstrator.

A command line interpreter window will open during the process. At some point you will be requested to enter some data, as in the following example

Country Name (2 letter code) [AU]: - e.g. GB (for Great Britain) etc.
State or Province Name (Full Name) [Some-State]: - England or whatever
Locality Name (eg, city) []: - London or whatever
Organization Name (eg, company) [Internet Widgits Pty Ltd]: - leave blank and hit return
Organizational Unit Name (eg, section) []:- leave blank and hit return
Common Name (e.g. server FQDN or YOUR name) []: your real name as known by Betfair
Email Address []: the one known to Betfair

You are then asked for a password. I didn't bother and just hit return. This password would have to be included in your authentication which already includes your username and password pair.

When the process is complete you will see four new files in the C:\OpenSSL-Win32\bin directory; 

client-2048.crt - your digital certificate
client-2048.csr - a certificate signing request
client-2048.key - your private key
client-2048.p12 - used to authenticate your application to Betfair

Your certificate file will be given to Betfair and your P12 moved to the root at C:\ and used in the login process. Copies of all should be saved somewhere safe offline.

7) Now login to the Betfair website. At the top of the screen, click My Account and then My Betfair Account in the dropdown menu. You will then see another dropdown menu called My details. Click on this and then Security settings. You will then see your security settings page. Click on the Edit link next to Automated Betting Program Access. You can now browse to your client-2048.crt file and upload it to Betfair. After the upload make sure the status is set to On.

8) For readers of my book you will need to alter your code for automatic authentication thus

a) Create a new Module called Authentication.vb (Use the module creation in the book as reference) and add the following code to it (remembering to replace the red words with your appropriate details). You will notice that the certificate location is expected to be in the root of the directory so you must move the P12 file that you created to there. If you want the P12 to be elsewhere then you must change the code.

Imports System.IO
Imports System.Net
Imports System.Text
Imports Newtonsoft.Json
Imports System.Security.Cryptography
Imports System.Security.Cryptography.X509Certificates

Module Authentication
  Public Sub Login()


      Dim postData As String = "username=YOUR_USERNAME& _

      Dim cert As New X509Certificate2("C:\
client-2048.p12", "")

      Dim request As HttpWebRequest = _

      request.Method = "POST"
      request.ContentType = "application/x-www-form-urlencoded"
      request.Headers.Add("X-Application: YOUR_APPKEY")
      request.Accept = "application/json"

      Using dataStream As Stream = request.GetRequestStream()

        Using writer As New _
StreamWriter(dataStream, Encoding.[Default])
        End Using
      End Using

      Using stream As Stream = DirectCast(request.GetResponse(), _
        Using reader As New StreamReader(stream, Encoding.[Default])
          Dim loginResponse As LoginResponse = _
JsonConvert.DeserializeObject(Of LoginResponse)(reader.ReadToEnd())


          SportsAPI.ssoid = loginResponse.sessionToken
          AccountsAPI.ssoid = loginResponse.sessionToken

        End Using

      End Using

      Catch ex As Exception
        Form1.Print(Now & " - Login Error: " & ex.Message)
      End Try

    End Sub

    'Class for non-interactive login
    Public Class LoginResponse
        Public sessionToken As String
        Public loginStatus As String
    End Class

End Module

The Print statement above in blue is a test that will print out your ssoid on successful authentication. Delete or comment out this line after testing.

b) Now change the Form1_Load subroutine in Form1.vb as follows

    Private Sub Form1_Load(sender As Object, e As EventArgs) _
Handles MyBase.Load


    End Sub

by commenting out the LoginForm.Show() statement as LoginForm.vb is no longer needed and then adding the call to the Login() subroutine in Authentication.vb, followed by the initialise() call that used to be in LoginForm.vb

You should now be able to access Betfair without having to type in your username/password pair. I recommend that you keep two-factor authentication on the manual login to the Betfair website as you cannot automatically login there. If there are any problems then let me know.

Further Reading

Programming for Betfair
A guide to creating sports trading applications, is now available on Amazon. You do not need any programming experience...

Edge, Expectation and Kelly Criterion

In the course of your research you have probably come across the terms edge and expectation. You may also have heard of Kelly Criterion, a method for bet sizing that optimisies maximal investment growth. All of these terms are important for good money management.

Edge is just another (and easier to remember) term for mathematical expectation. The calculus of expectations is attributed to the Dutchman Christiaan Huygens, an early probability theorist. Expectation (also known as expected value) is defined as the weighted average of a variable. In gambling theory, expectation is the average expected rate of wealth accumulation. For any gamble, you are either going to win or lose your bet and so expectation is the sum of your average winnings plus your average losses, and is given by the following formula

where p is the probability of winning, profit is the profit from a £1 bet and loss is the loss of that £1 bet. Taking American roulette as an example we can determine the house edge in the long run. The wheel in American roulette has 36 numbers from 1 to 36, 18 of which are red and 18 are black. There are also two green numbers 0 and 00. Betting on the colour red or black will earn you even money on a winning bet. The house wins in the long run because of the two green numbers at the rate of

where (20 / 38) is the probability of someone not hitting their chosen colour (the 18 numbers of the other colour plus the two green numbers) and (1) is the unit bet. If the gambler should win then the probability of that ocurring is 1 - (20/36) and the house loses a unit bet (-1). We calculate the house edge to be

so that for every bet on black or red guarantees the house a profit of 5.3% in the long run. There is no bet on green and that is where the house gets its edge. If the house is winning 5.3% then the general public is losing 5.3% and no amount of Martingale betting is going to change that fact.

Kelly Criterion was developed in the 1950s by John Kelly, a colleague of the information theorist Claude Shannon. Using Shannon's information theory Kelly determined the optimal bet to maximise the growth of an investment. Kelly derived the following formula

where f is the fraction of your wealth to be invested, p is the probability of a winning bet and b is the net odds returned (also called yield) on a £1 winning bet. For the roulette example above the recommended fraction of your wealth to bet is

Two things to note here, firstly that the Kelly Criterion is telling you to invest a negative amount of your welath. This is because the bet has negative expectancy therefore you should bet nothing in this instance. Secondly, if you calculate the numerator (top part) of the Kelly Criterion formula then (18/38) (1+1) - 1 = -0.053, which is the same as the expectation for the player. In other words p (b+1) - 1 is just another way of calculating expecation (or edge) and the Kelly Criterion can be re-written as 

And so, good money management first determines whether or not an investment strategy has an edge and then by using the predicted average yield you can calculate what percentage of your wealth to invest. For example, if the expectation for a given strategy is 0.056 and the average odds offered are 2.20 giving a yield to £1 of 1.20 then you should be investing 4.7% (0.056 / 1.20) of your net worth on each bet.

Algorithmic Trading

My own trading revolves around the algorithmic trading of horse races. In particular, I am looking to get ahead of the crowd through low-latency trading, following trends caused by the flow of late-breaking information, statistical arbitrage across markets, non-fundamental pricing algorithms, spoofing, bot baiting, synthetic bets and so on. Research is always on-going as strategies can lose their edge and new strategies evolve.

There is a lot of commonality between what I do and what goes on in the financial markets. Namely, I am looking for an edge in any way that I can but without any fundamental analysis. A lot of the time, in this zero sum game, you are preying on the mistakes and naivety of others.

As I am not a fundamental trader I don't read the horse racing news. I have watched the Grand National a few times when Red Rum was running, one or two Epsom derbies and a few Royal Ascot meetings, mainly through boredom rather than any desire to see horses run.
What I do read is how quants trade financial markets. I have no desire to trade in the financial markets myself and have the HFT (high-frequency trading) firms leading me by the nose. I read books about financial algorithmic trading and architect similar methodologies for sports trading markets.

Some of the books that have assisted me in building an algorithmic trading platform are listed here.

The basis of any algorithmic trading platform is the black box through which a portfolio of trades is assembled and executed. In Inside The Black Box you are given the architecture of a black box; the alpha model (the money making strategy), the risk model (minimisation of drawdown), the transaction cost model (trading cost efficiently) and the portfolio construction model (taking the portfolio of positions from the current position to a more profitable one).

The book describes order execution algorithms, the importance of data when creating new strategies, researching new strategies, quant strategy evaluation and a discussion on high-frequency trading. Although the book obviously discusses this in a financial trading context, the information within is an excellent guide to creating a black box for trading sports betting markets.

Amazon - Inside the Black Box: A Simple Guide to Quantitative and High Frequency Trading

Building Winning Algorithmic Trading Systems is written from the viewpoint of a highly successful independent trader, Kevin Davey. His methods are similar to mine in his use of data to create strategies and Monte Carlo simulations to test them.

The book takes you from the beginning of the author's trading career and his demonstration of why not to trade under psychological stress. Davey was still trading a week after two traumatic deaths in his family. Trading on whim he invested in live cattle futures the day before the US announced its first case of BSE, a fine example of a black swan event (see The Black Swan: The Impact of the Highly Improbable).

After dabling with other beginner's mistakes such as simplistic that were not sufficiently tested, Davey started chasing his losses by averaging down, in the hope that the market would turn only to compound his losses yet further. Davey re-evaluated all that he thought he knew and started again. He learned how to create strategies that were devoid of human interaction and properly tested so that none of his frailties affected his trades. This results were impressive, two seconds and a first in the World Championship of Futures Trading.

For more than twenty years Davey has created thousands of systems, tested them using walk-forward analysis and then determined the optimal position size using Monte Carlo simuations. All of which is detailed in this book. Because Davey's approach is so similar to mine I need only recommend his book and not have to tell you myself.

Amazon - Building Winning Algorithmic Trading Systems: A Trader's Journey From Data Mining to Monte Carlo Simulation to Live Trading

Programming for Betfair is written by the author of this website. The book is a guide to creating applications for direct access to Betfair's exchange and will therefore be useful to those wishing to implement an algorithmic trading set up using the other books listed here.

No previous programming experience is necessary to build the applications in the book. After completing the programming exercises the reader will have a powerful tool for gathering prices for database creation, strategy building and algorithmic trade placement. Beginner programmers and experienced programmers have informed me that the book is easy to understand and that it has assisted them in creating algorithmic trading platforms.

Amazon - Programming for Betfair: A Guide to Creating Sports Trading Applications with API-NG

Without winning trading strategies your algorithmic trading operation is not going to be profitable. The Encyclopedia of Trading Strategies is a complete guide to many of the methods used in optimising and statistically analysing trading systems. Models for trade entries are covered through breakout models, moving average models, oscillators, cycles, neural networks and genetic algorithms. Exits are then covered with AI approaches included. There is even some whacky lunar and solar rhythms included but we won't talk about that.

Again, the book is entirely geared towards financial trading and it is up to the sports trader to filter out relevant information.

Amazon - The Encyclopedia of Trading Strategies

If you want to use machine learning for the optimisation of your trading systems then Biologically Inspired Algorithms for Financial Modelling is a book dedicated to that task. Covering neural networks, evolutionary computation (genetic algorithm, genetic programming, evolutionary algorithms etc.), swarm, ant colony and immune system models the book exaplains how these methods work and their applicability to the creation of trading rules.

The second part of the book details model development from project goals, through data collection, to optimising for trade entries, exits and money management. Part three of the book contains case studies of index prediction and trading. A book for the more advanced quants amongst us.

Amazon - Biologically Inspired Algorithms for Financial Modelling

Inside the Black Box

The subtitle of Inside the Black Box is "A Simple Guide to Quantitative and High-Frequeny Trading", which means it is of interest to algorithmic sports traders. Starting with quantitative methods in algorithmic trading, the book discusses the importance of the mathematical understanding of markets rather than blind data mining methods.

The difference between the two is subtle but important as data mining can discover short term anomalies that are unprofitable when used as indicators for trading. A model should be theory driven. In other words prove why something happens and then model it rather than observing without understanding as is sometimes the case in data mining.

Following chapters discuss a modular approach to building a black box trading system. The black box is split into an alpha model (the money making strategy), a risk model (to control drawdowns) and a transaction model (to execute the trade as cheaply as possible). Finally, there is the portfolio construction model which uses the previous three models to build a portfolio of trades that will make as much money with the least amount of risk and with the optimal amount of capital. The book continues with execution algorithms, the importance of data and its usage in model building, researching trading strategies and evaluating strategies.

For sports traders who are new to algorithmic trading this book makes for a good framework with which to base a black box trading application. In terms that a sports trader would understand the alpha model is created by looking at data and generating hypotheses for its behaviour. The risk model is for creating stops and limits to handle unforeseen circumstances. The transaction model for sports trading would involve looking for the best prices, factoring in commission and bonuses and/or the use of synthetic bets to mimic the required bet but at a superior price or lower cost. Finally, the portfolio construction model takes all three models to build a portfolio of trades for a day's trading to optimise return on investment.

The book also covers evaluating quantitative methods and high-frequency trading. Although high-frequency trading is not really possible in sports trading (see Programming for Betfair: A Guide to Creating Sports Trading Applications with API-NG), you can think of it as low-latency trading and the optimisation of your hardware and software to be as fast as it can for the job at hand. This book is a very good introduction to algorithmic trading.

See also

Time to Trade Tennis

Tennis is my favourite television sport, after cycle racing. The sport is also my favourite sport to play now that I am getting on in years and am no longer able to cycle at the level I once did. I have never considered trading tennis before because horse racing was sufficiently challenging but with my book out of the way I have time to consider new projects.

The sport of tennis is relatively simple to model as the sport is a head to head between a pair of players or a pair of partners in doubles. Unlike football there is always a winner in tennis so the draw is not a consideration. With the exception of Davis/Federation Cup games there is no concept of home and away. The days of home nations dominating Grand Slam tournaments are probably over. 

The scoring system in tennis favours the player who wins the most points (an obvious statement to make but stay with me). This can be seen in an interesting simulation using Monte Carlo methods created by Michael Maboussin author of The Success Equation. If you click on the following link then you will see the simulation in action.

Tennis Simulation

With players of equal ability the probability of either player winning the game is 0.50 but you only have to play around with the simulation to see that a player who is only marginally better than another player has by far the greater chance of winning a match. Indeed with a 57.7% chance of winning you guarantee victory with a 1.0 probability of winning the match. I can vouch for that personally. Being rather middle-aged and decrepid I tend not to play singles games as I am guaranteed to lose. I am better suited to the slightly more static role of net poaching in doubles.

In reality not all games go the way a simulation might have you believe. The top seeded players lose games for a variety of reasons. Their abilities might be waning but it takes time for them to drop down through the rankings. A player might treat a tournament as a training exercise and withdraw after a couple of rounds or their mind might be on a more prestigious future tournament and they make too many mistakes and lose a match to a lowly ranked player.

Data for tennis matches is very easy to come by and is usually free. There are also websites where you can match up a pair of players to see how they faired against each other in the past. Once such site is MatchStat and can be found at the following link.


Just enter the names of the two players in a singles match and you will be shown their previous matches against each other. However, it is not just a simple matter of creating a probability from the number of times a player has beaten another. As you will see in MatchStat, games are played on different surfaces with some players preferring one surface to another. The players at the top of the ATP rankings will be mindful of their ranking points and build their season around the bigger tournaments such as the four Grand Slams and the ATP Tour Masters 1000 tournaments. The lucrative ATP World Tour final at the end of the year is also borne in mind too.

Currently, I am working on my own Monte Carlo methods simulator, which will allow the user to model some of the aspects mentioned above and permit "What if?" scenarios to determine how various factors alter the probability of winning a tennis match. With probabilities you can derive odds and use them as a basis for trading with.

See Also

Tennis Citations - Some academic work on tennis trading

The Hidden Mathematics of Sport - Contains useful mathematical facts on tennis and other sports

Back to Work

Completing the book was a long six months, full of doubts and rewrites. I am glad that the book is finished so that I can contemplate new projects.  But just because I have put all my code into a book doesn't mean that I have nothing left to write on this blog. My observations of bot trading on Betfair will continue and decrying some of the nonsense you read elsewhere.

There is more code to write, which will probably find its way into another book in the years to come. Then there are my investments to catch up with. I am very much a believer of "getting rich slowly". Not everyone can be an Elon Musk or Richard Branson, creating a string of successful money making products. In fact, very few of us can. It's all part of the normal distribution. There is little space at the top of the distribution peak for many people. Every winner needs a loser and every big winner needs a lot of losers. 

Be happy with what you have and make the most of it. By all means try to improve your lot but don't gamble for it. Invest wisely with your time to increase your knowledge and invest wisely with your capital to increase your wealth. There are many who win big only to lose big later. You can make a lot of money quickly and lose it just as quickly. It's all about risk and reward. The more risk you take the bigger the reward but also the bigger the potential loss. 

I am sure you have seen plenty of blogs where people run up large wins at the beginning and then the blog ends abruptly. Blogs where people proudly boast their winnings but withhold their losses, even manipulating the figures or starting over so as to hide their failings. Sports trading is only a small part of what I do. I am in no hurry to make large sums of money. Approaching my fiftieth year means that the money I have gained from working for others is all the money I will ever have from that route and so I have to invest wisely. Today I only earn what I can scrape off the Internet. I have money in Peer 2 Peer investment sites, I write about trading, I code trading strategies, I do the odd consultancy job, gathering money here and there. My life is varied and its my own. No nine to five and no manager. Time for a holiday.

Programming for Betfair

Programming for Betfair, a guide to creating sports trading applications, is now available on Amazon. You do not need any programming experience to create the applications, just a logical mind.

Using the freely available Visual Studio I show the reader how to build an application that gets prices from and places bets automatically into Betfair's exchange. Also, the reader can build databases from Betfair data for offline analysis. Data can be saved whilst the trading application is running and then converted into a CSV format for a spreadsheet where it can be manipulated, charted and analysed for the creation of trading rules.

There is also a chapter on improving the charts on Betfair's website. Charts can be grouped together for comparison and updated automatically to keep the trader up to date with the latest trends in the market place. The final chapter touches on some advanced techniques such as the creation of trading indicators, volume analysis (specifically VWAP - volume weighted average price), low-latency optimisation, arbitrage, machine learning, Monte Carlo methods and more.

Some Screen Captures from the Book

Betfair's visualisers are used to demonstrate how JSON is used to communicate between the reader's computer and Betfair's servers. The reader is then gently led through the creation of JSON request strings and the processing of JSON response strings into raw data for use by the application.

The price engine with a bet placement control for experimenting with various bet types. The user is then shown a non-graphical way of inserting bets into the exchange for automated trigger betting.

A ChartBot can easily be created for multiple views of Betfair charts, side by side. They can also be set to auto-update.

The application created in the book can build databases of data for offline analysis in a spreadsheet so that the user can analyse the data and build trading rules.

For the contents of the book click here. (PDF format)