A Poker Bot Comment Worth Reading

This is post #13 in an ongoing series of articles about my work as a poker bot developer.

An anonymous poster left the following comment on my last poker bot post:

Hi Matt,

very, very interesting article series — please keep it up if you have more material.

I’ve also written a bot. It started as a little helper tool for my own, manual SNG-playing, showing a HUD on the table with the other players’ OPR stats etc etc. Having that in place, I couldn’t resist the temptation to see how hard it would be to do some table scraping, and when it turned out that was really straightforward, I started coding up a little rule-set that I believed would be able to win at low-stakes SNGs, where play is less than stellar…

After about 4-5 weeks, of off-hour, hobby programming during some evenings and weekends (I have a family with two small kids, so time is limited), I had it absolutely *crushing* the 18-man turbo $1.75 and $3.40 SNGs on Pokerstars — with a 50% ROI vs the field (ie not counting the rake). Actual ROI (counting the rake) was ~35%.

Table scraping etc was effective enough that the bot could easily 24-table (and probably way more — I never tested with over 24), but I kept it at 12-18 simultaneous games, to not go completely overboard on the volume.

After about 1.5 months, and 6-7k games, Stars’ security team busted me. I’m not sure what triggered it — it might have been a captcha I missed (I usually just left the bot playing overnight while I was sleeping…), it might have been decision patterns that set off an alarm, it might have been things they scraped off my computer (mouse movements or something like that — although as you also mention, I believe that’s actually quite unlikely, as they will get an insane amount of false positives, for TableNinja users etc), or — most likely — it might have been the volume that led to a manual investigation of the account.

Just before I was busted, there were seemingly random changes to the layout of the hole cards and board cards, and they were sometimes antialiased a little different. That was probably a trap in the Stars client that they can trigger from the server side, to see if the other side starts timing out or doing something else stupid. And my bot obviously fell right into it.

A couple of days after that happened, I then got the same email you got, about terminating my account, confiscating the money I had (I had made a withdrawal the day before, so that was a tiny sum), and expelling me forever from playing at Stars.

Oh, well. It was a short but interesting ride — but as you also say, it wasn’t really worth it.


And wow: 4-5 weeks to program a winning low stakes SNG bot with a 35% ROI. That’s pretty remarkable.

I’ve always had a suspicion that the abnormally high number of HUSNGs that my bot played/day was what ultimately led to its demise. I suspect that may be the case here too: 6-7K SNGs in 6 weeks–I bet that’s quite an outlier ;)

Another thing he mentions is the seemingly random changes to the layout, which I can also attest to. The tables would randomly resize by a few pixels, which would normally be imperceptible to a human player but for a bot that depends on certain pixels being in exact positions, it causes a lot of trouble.

Anonymous poster whoever you are, thanks for the fascinating story.

5 thoughts on “A Poker Bot Comment Worth Reading

  1. Can you tell where the PokerOfice chat is?

    Anyway, I’m trying to crack down table scrapping at poker stars and I getted that PokerOffice does some dll hooking but I can’t discover how the dll does it. Any ideas?
    Dll dissamble seems crazy enough but it’s kind of hard too

  2. Hmmm, so if pokerstars randomly resizes the table screen by a few pixels your bot crashes… but how does POKER TRACKER HUD work, I dont think it ever crashed for me, so there must be a way around this.

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