Pluribus Poker AI Overbets

Pluribus Overbets on the Flop (Poker AI)

Pluribus overbets are probably the most talked about behavior of the Poker AI. Yet we don’t know that much about these and, boy, are they ugly ! In the poker games I play, there are quite a few overbets on the turn with a combination of nuts and draws, overbets on the river with nuts or air. However overbets on the flop are super rare, other than the fish wanting to go all in preflop and as it doesn’t happen, shoves on the flop with his JJ or AKo whatever the board… or overbets on limped boards which well, family pots, who cares? But overbets on a normal heads-up single raised pot, I really see few of them.

Pluribus bets 200% pot on almost 10% of her Cbets. Now 200% is not a number Pluribus gradually optimised based on machine learning training or anything like that. On single raised pot, the researchers only allowed for 3 bet sizes: 50%, 100% or 200%. So the actual size really means nothing.

So in total, on the flop, Pluribus overbets the flop 27 times. In the following chart, I detail the kind of flop (single raised pot, 3bet pot, or limped raised pot), whether Pluribus was the agressor preflop, the position with detail, Pluribus hole cards, the flop cards, comments I could come up with, and range vs range equity for the flop (based on standard upswing ranges, not my estimated Pluribus ranges):

Pluribus Poker AI Overbets
  • What can I add to this ?
  • The majority of Pluribus overbets are IP vs BB , hence with a significant range advantage on most flops giving the opportunity to bluff at a given frequency
  • The range advantage of these specific flops is not particularly better than for random flops at the same positions.
  • The out of position and limped/raise Cbets seem super logical
  • The 2 overbets while defending are just super weird to me, especially the one donking multi way, looks like what the few remaing donk fishes still do in 1-2 live games. Probably just low low percentage AI weirdness.
  • Interesting to note, only 1 of these 27 overbets got a call and none a raise
  • Looking at this, it looks super exploitable to me, like reraise each time Pluribus overbets as the preflop agressor in position in single raised pot.
  • Obviously, I just don’t get it… Not a behavior I’ll add to my game ?
  • Tell me what you think, I can’t wait to have someone more competent than me analyse this !

Author: Yolanda Wade