A comment, an icon, rounding and an offer.

Drive Blind commented –

US Horse Racing Off Times have been a problem for bot developers since the year dot. The US off times are just a guide and are not religiously adhered to like the rest of the world. Initially I got around this by polling the Time to Post stat that gives a guide of when the off time is due. This value can be scraped from a number of different sites. Even this was a little hit and miss. What I eventually landed on was waiting till the overround was less than 105% to indicate that the race was about to go off. Works quite well in sparse US markets where all the money comes in at the end before the off.

Thanks for this comment. I’ve looked into scraping times and have found a few sites. Not made any attempts to integrate yet. The idea of watching the overround is very good and something I hadn’t thought of. This goes on the to-do list, thanks.

 

 

I’ve been coding an app in Visual Studio to replicate a spreadsheet I’d made when I was doing the matched betting thing. I added an icon and thought I’d add it to this site, so if you haven’t noticed, it should be at the top of the address bar and look like this –

I like the simple look, which is fortunate. And it should show up as different to WordPress in any bookmarks, or in the blog roll on green-all-over (It’s been quiet over there recently).

 

The app I’ve made calculates the lay stake at given odds. A problem I encountered whilst testing my little app was a difference between what I calculated and what I was seeing on the Betfair site. It’s only small but at large stakes it’s noticeable and any discrepancies are worrying, suggesting an error in the formula used. My error came down to rounding. Initially I was just rounding the result only to 2dp. Each step of the formula requires rounding to 2dp to keep it accurate. At no point can you place a lay stake of £50.083333. Attention to detail is key, my mistake.

 

Talking of attention to detail, I recieved an offer to try out a VPS in Dublin with less than 3ms delay. That’s extremely fast for sports trading and probably as good as it gets without co-location (something I’m sure goes on). I had looked at getting a Dublin based VPS when I was setting up but was not willing to pay the obvious premium rate. The offer I received came via Twitter and the first thing anyone does is look at the website of the people making the offer. I remember this company was looking for people to trial its VPS about a year ago. Their website still has some pages that haven’t been altered from the template settings – the blurb you get when you start a website from a pre-made layout offered by these site builder outfits. There’s a lot of trust when putting your bots onto a VPS and you want to know you’re in safe hands that pay attention to detail. I declined the offer.

How’s it going?

Automated_trader commented –

“How’s coding your own bot going? I got a copy of Programming for Betfair today so gonna try and code my own too. I’ve no coding experience other than a little VBA for my current bots that run on Gruss so hoping it won’t be too big of a leap into the unknown. Might even start a blog to document my progress too.”

The coding is going really well with a bot now in testing. I doubt I’d have started without Programming for Betfair as I thought the amount to learn wasn’t worth it. The book helps by giving you everything you need to start auto trading, as in it gives you the code to request data, place bets and handle the responses from Betfair. It also gives you the basic tools to trade with such as profit take, fill/kill and stoploss. Once you’ve worked through the book, it’s just a case of adapting what you’ve learnt to get what you want.

My currently running and previous bots are written in VBA and running through Gruss. Before I started them I hadn’t written in VBA but picked it up from forums and searches. I hadn’t done any VB.net prior to this but understanding it isn’t that much of a leap. It’s the same style of object programming and the terms and layout are familiar after using VBA.

It’s true that any errors (after the corrections on the associated website are completed) are down to typos. A couple of times I thought it wasn’t me and something must have changed making the code not work. But it was me, with one mistake being a missing “A” in an url string. That took hours to find and I’d looked at the offending line of code more than once. Another biggy was missing a whole line of code, again taking forever to find. Sometimes the error message isn’t that helpful, not to me anyway. This one was an “overload” which, I’ve since found out, means you’re trying to put more variables into an object than you have declared. That’s what the missing line was, a variable declaration.

Some things to note, firstly, Visual Studio (VS) uses IntelliSense which highlights errors as you go. To begin with, this is quite annoying as you’ll finish a module and there’s a list of errors, so you spend time looking for what you’ve done wrong – which is nothing. The errors disappear when you complete the next couple of pages in the book. I found it’s better to ignore most of them until you get to a point where the book tells you to try running the code. The ones to correct as you go are missing or expected characters, such as “(“ expected.

Second – VS includes an autocomplete function. This will really mash your head at some points as you try to add a new declaration and it changes it to something else. If this happens, a quick tap on backspace should swap it back to what you typed.

Third – I find that the first run of the code after starting VS can sometimes fail. Just stop and run again. This problem goes once you publish your project.

If you enjoy coding you shouldn’t have any difficulty with it, just need patience. Let me know how you get on.

Null exception

Wasted 2 hours trying to get some code to run but, as it’s been so long since I started this, I kept getting a null exception. Every line reread, sometimes twice, then eventually noticed a string I’d written in mixed case. For all the auto correction this Visual Studio does, it isn’t magic, I must concentrate.

 

Milestones

Well they are to me. Towards the end of last week, the total number of markets I’ve taken part in topped 40,000. I like numbers. To think my bots have monitored at least double that amount of markets is amazing.

The second point came on Sunday when my balance hit three figures. In reality it’s irrelevant but visually, it’s encouraging.

And last but not least, bring out the bunting, I’ve started coding my very own bot using Programming For Betfair. Once I started I found visual studio easy to get on with, similar to the VBA IDE but better, a lot better. It was a little annoying at first with it’s auto correct and finish features (it adds end statements automatically but I keep typing them, giving two lines of the same thing) but I’m getting used to it. Can’t wait to get it running my own algorithms, the possibilities are endless…