So I’ve been getting back into poker recently (both online and live) and I recently stumbled upon a very interesting player in a low stakes PokerStars tourney. This player was pretty conservative, took the same exact amount of time to make a decision, and made the same size raises when it bet. These observations made it relatively safe to assume that I was playing against a poker bot!

I’ve always heard of poker bots, but I never had the privilege of playing against one. So when it was just Mr. Pokerbot and I heads-up at the once 9-player table, I was excited yet scared of actually losing to a bot.  But I would think that my years of poker experience would allow me to beat the bot with relative ease.

It turns out that I was right.  I noticed from previous hands that it was playing pretty tightly..a little too tightly.  So when I was dealer, I would always min-raise it and it would fold.   And when it was dealer, it would always call the big blind, I would always min-reraise it, and it would always fold again.  This happened for about 15 hands in a row of me stealing the blinds until finally it re-raised me all in.  Of course I would be a fool to call that with anything but aces which I didn’t have.  So I folded that and just continued my strategy of min-raising and min-rerasing until it eventually blinded out.  Pretty easy huh?

Well I played another game today and encountered yet another bot.  This one was significantly harder to identify.  I actually wasn’t sure that it was a bot until there were about 3 players left.  It was also conservative, but it would have very timed aggression, re-raiasing all in to steal some blinds from unsuspecting limpers.  In addition, it would use a variable amount of time to make each decision.   But it was too variable.  While better than just using one specific time interval to make all decisions, using a pure randomized time to pass as a human player won’t cut it either because it’s just not consistent with what the average human player will do.  A human player will make the majority of their decision within 4 seconds with the occasional longer pause for critical decisions in larger pots.  This particular bot would, on many occasions, wait 10+ seconds just to fold a hand preflop and would instacall a lot of other bets.   Of course it was still within the realm of possibility that it was human, just very unlikely.  But when it came down to two players left, I was all but certain.

So once again it was me against  Pokerbot 2.0 heads up (if this isn’t an indication that players on PokerStars are so awful at the game, I don’t know what is).  I decided to use the same strategy that I did with the other bot.  I would min-raise/min-reraise.  But this bot was definitely smarter.  It would flat out fold about 2/3 of the time and re-raise all-in the rest.  It would never just call.  It used the same all-in or fold mentality that I had seen with the other bot.  I realized that with these folding ratios, I could probably keep with this strategy and blind it out, although, it would take a lot longer compared with the previous bot encounter.  So I eventually I got the chip ratios up to 3:1 in my favor.  And then I noticed something a bit surprising, it was re-raising all-in a lot more frequently.  Was it just getting really lucky and catching a lot of high quality starter hands? or was it actually getting… “smarter”?  I didn’t know what was up, so I decided to be more cautious.  I was still winning, but the chip ratios looked more like 2:1 in my favor.  I decided to abandon my previous strategy and started to play more like I would against a human player.  I would raise all-in rather than min-raise whenever I had a decent holding.  It eventually called one of them with an Ace-low against my QJ suited.  The bot ended up doubling up making the chip stacks even.  Lucky bot… catching an ace when I had almost blinded it out.  Perhaps that was the criteria for calling,  an Ace?  It was being a lot more aggressive now folding about 1/3 of the time and raising 2/3 of the time.  Was it really reacting to my decisions?  Or was it just noticing that the blinds were increasing to a point where all-in was pretty much the only move?  Probably the latter, but in any case, kudos to the programmer for allowing it to react accordingly.  Eventually it came down to an all-in where my hand was dominating.  (K-7 vs K-5 if I recall -  there goes my Ace theory)  And of course the bot would catch a 5 and take all my chips in the process.

Well nonetheless,  it was a very interesting game and I think in this particular game I just got really unlucky with the cards.  But that bot still managed to get the best of me and 7 other players at the table so that should count for something.

gg Pokerbot 2.0.