[codethief]

> I believe they have beaten poker professionals in thousands-of-hands playoffs

I really don't know anything about poker AIs but could it be you are referring to Libratus and/or Pluribus[0]?

[0]: https://noambrown.github.io/

[bubblyworld]

To be honest I didn't have a specific AI in mind, more the technique, but it sounds like these ones also use a variant of CFRM.

[energy123]

I do not believe these attempt to exploit regularities.