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I am the solver programmer mentioned in the article. I think it came out pretty decently. Maybe not all the details are right (I was late answering fact checkin

I am the solver programmer mentioned in the article. I think it came out pretty decently. Maybe not all the details are right (I was late answering fact checking email) but I think it's a decent read and the author has done a good job!

im3w1l 5y ago
How perfect is the play that piosolver calculates? Do you make any simplifying assumptions? I noticed in the article that piosolver can incorporate a mixed strategy with multiple bet sizes. Pretty neat, is that a recent feature? As I rememember it, a few years back people would discuss what the optimal bet size was in various situations with the implicit assumption that there is just one.
- bluecalm 5y ago
  Adding multiple betsizes was one of the first features we added in 2015 - so not very recent, no. The one true correct bet size is a seducing idea but that just doesn't exist for most situations. You can try finding the best one with the assumption you can only use one but it's not the best idea in my opinion. Main reasons are that that's the sizing most people will be most ready to play against and EV difference between possible bet sizes is minimal. What happened in chess is now happening in poker: at first people were all about the best theoretical move and then gradual shift to "not necessary the best just sound enough but less likely to be analyzed by the opponents" started happening. As to the first part of your question: the solutions are pretty much perfect. The only assumption is about possible bet sizes. As to accuracy we measure it in theoretical exploitability (how much a perfect adversary who knows our strategy exactly could win against us). You can easily go so low that even a theoretical perfect adversary wouldn't get close to beating the rake vs the solution, even at high stakes.
  - deleted 5y ago
    [deleted]
ewhauser421 5y ago
Congrats - PIOSolver is an amazing program. What are the future plans for it? It would be great if you didn't need a PhD to set it up though. I keep wondering if I'm actually training myself using the right solutions or not based on the setup :)
- bluecalm 5y ago
  The plans are to start turning it into real company which hopefully means easier to use software, more learning material and better communication. Till now it was mostly two guys working from home and overwhelmed by it all.
michalsustr 5y ago
Congrats on putting this together, it's not easy! I'm curious, what papers have you used for your implementation? I know there are a couple of reimplementations of DeepStack out there. Disclaimer: I'm doing phd in this area, generalizing to harder games than poker.
- bluecalm 5y ago
  The solver was purely based on our (mine and my partner's) ideas. We tried reading some papers to find ideas to improve our solver but we had found that they are not very helpful - written in opaque language, using wrong tree representation and not focusing on practical implementation aspect. Maybe things changed since then but I haven't found anything useful at all in published papers about poker with the exception of two page one by Oskari Tammelin describing CFR+ algorithm (which we haven't used in our software because of its significant memory requirements). We considered it very unlucky that the science paper was published as we thought more people will implement solvers then (ours was ready in mid 2014 and we released and a working solver with a GUI in early 2015, 3 months after the Limit Holdem paper). As it turned out though it didn't really matter much. I had an idea to code a poker solver around 2008. Unfortunately I was yet to learn to code back then. The biggest challenge was to overcome implementation issues. Once I got the crucial part to be fast enough I knew the solver is possible. I think not having much background in the field allowed me to come up with more natural (and better) tree representation and memory efficient (even if not the fastest) algorithm as I was thinking more as poker player than a computer scientist back then.
  - michalsustr 5y ago
    Interesting! We have very recently wrote a paper on the various tree representations [1]. Maybe it is the same distinction you found on your own? I judge this based on the screenshots on your website. Public state trees are amenable to nice factorization over the hands, and indeed most implementations use it, but formally they write they use the history tree notation. [1] https://arxiv.org/abs/2112.10890 https://arxiv.org/abs/2112.10890
    - 5y ago
muldvarp 5y ago
2016 you said "It's a very small niche and getting less popular but we are still doing very well." Did this turn out to be true or has PioSOLVER become more popular again?
- bluecalm 5y ago
  I think poker in general is slowly dwindling but somehow the solver in fact got more popular over the years. I think the pandemics helped us a bit and maybe general switch to nie analytical play. To be honest I don't understand it very well. We have never done any marketing, our website is terrible (put together on a free Shopify template and never really updated) but somehow it keeps getting more traction.
sillysaurusx 5y ago
How did you end up working on this? It’s an interesting history.
- bluecalm 5y ago
  I was always interested in math and encountered game theory concepts early in life. It's a perfect mix of being not a very good programmer, not a top math mind, not an exceptional poker player but still being all those things at the right time and place.
  - sillysaurusx 5y ago
    I really like that you got to do this, and that you turned your weaknesses into such a great strength. Thank you for showing that you don’t need to be exceptional in a specific area to do exceptional work. Best of luck with whatever you decide to pursue next.
dabei 5y ago
Great job! What makes PioSolver much more popular than the other solvers?

im3w1l 5y ago

How perfect is the play that piosolver calculates? Do you make any simplifying assumptions? I noticed in the article that piosolver can incorporate a mixed strategy with multiple bet sizes. Pretty neat, is that a recent feature? As I rememember it, a few years back people would discuss what the optimal bet size was in various situations with the implicit assumption that there is just one.

bluecalm 5y ago
Adding multiple betsizes was one of the first features we added in 2015 - so not very recent, no. The one true correct bet size is a seducing idea but that just doesn't exist for most situations. You can try finding the best one with the assumption you can only use one but it's not the best idea in my opinion. Main reasons are that that's the sizing most people will be most ready to play against and EV difference between possible bet sizes is minimal. What happened in chess is now happening in poker: at first people were all about the best theoretical move and then gradual shift to "not necessary the best just sound enough but less likely to be analyzed by the opponents" started happening. As to the first part of your question: the solutions are pretty much perfect. The only assumption is about possible bet sizes. As to accuracy we measure it in theoretical exploitability (how much a perfect adversary who knows our strategy exactly could win against us). You can easily go so low that even a theoretical perfect adversary wouldn't get close to beating the rake vs the solution, even at high stakes.
- deleted 5y ago
  [deleted]

ewhauser421 5y ago

Congrats - PIOSolver is an amazing program. What are the future plans for it? It would be great if you didn't need a PhD to set it up though. I keep wondering if I'm actually training myself using the right solutions or not based on the setup :)

bluecalm 5y ago
The plans are to start turning it into real company which hopefully means easier to use software, more learning material and better communication. Till now it was mostly two guys working from home and overwhelmed by it all.

michalsustr 5y ago

Congrats on putting this together, it's not easy! I'm curious, what papers have you used for your implementation? I know there are a couple of reimplementations of DeepStack out there. Disclaimer: I'm doing phd in this area, generalizing to harder games than poker.

bluecalm 5y ago
The solver was purely based on our (mine and my partner's) ideas. We tried reading some papers to find ideas to improve our solver but we had found that they are not very helpful - written in opaque language, using wrong tree representation and not focusing on practical implementation aspect. Maybe things changed since then but I haven't found anything useful at all in published papers about poker with the exception of two page one by Oskari Tammelin describing CFR+ algorithm (which we haven't used in our software because of its significant memory requirements). We considered it very unlucky that the science paper was published as we thought more people will implement solvers then (ours was ready in mid 2014 and we released and a working solver with a GUI in early 2015, 3 months after the Limit Holdem paper). As it turned out though it didn't really matter much. I had an idea to code a poker solver around 2008. Unfortunately I was yet to learn to code back then. The biggest challenge was to overcome implementation issues. Once I got the crucial part to be fast enough I knew the solver is possible. I think not having much background in the field allowed me to come up with more natural (and better) tree representation and memory efficient (even if not the fastest) algorithm as I was thinking more as poker player than a computer scientist back then.
- michalsustr 5y ago
  Interesting! We have very recently wrote a paper on the various tree representations [1]. Maybe it is the same distinction you found on your own? I judge this based on the screenshots on your website. Public state trees are amenable to nice factorization over the hands, and indeed most implementations use it, but formally they write they use the history tree notation. [1] https://arxiv.org/abs/2112.10890 https://arxiv.org/abs/2112.10890
  - 5y ago

muldvarp 5y ago

2016 you said "It's a very small niche and getting less popular but we are still doing very well." Did this turn out to be true or has PioSOLVER become more popular again?

bluecalm 5y ago
I think poker in general is slowly dwindling but somehow the solver in fact got more popular over the years. I think the pandemics helped us a bit and maybe general switch to nie analytical play. To be honest I don't understand it very well. We have never done any marketing, our website is terrible (put together on a free Shopify template and never really updated) but somehow it keeps getting more traction.

sillysaurusx 5y ago

How did you end up working on this? It’s an interesting history.

bluecalm 5y ago
I was always interested in math and encountered game theory concepts early in life. It's a perfect mix of being not a very good programmer, not a top math mind, not an exceptional poker player but still being all those things at the right time and place.
- sillysaurusx 5y ago
  I really like that you got to do this, and that you turned your weaknesses into such a great strength. Thank you for showing that you don’t need to be exceptional in a specific area to do exceptional work. Best of luck with whatever you decide to pursue next.

dabei 5y ago

Great job! What makes PioSolver much more popular than the other solvers?