The Truth about Pluribus Poker AI Donk Bets

Much has been said in the press about Pluribus Poker AI donk bets. In their press release, Facebook says “ Pluribus disagrees with the folk wisdom that donk betting (starting a round by betting when one ended the previous betting round with a call) is a mistake; Pluribus does this far more often than professional humans do. ” So is it the case, how much, and in what specific context ?

Carnegie Mellon University published 10K hands played by Pluribus against the pros. So we can have a deep look at donk betting by Pluribus, but also by the pros. I’ll focus only on single raised pots, ie when there is only an open and a call preflop and no reraise/3bets. 3bet pots have a very different dynamic and there are less of them to look at.

As a reminder a donk bet is a bet where the preflop defender (player who just called) is out of position and leads the betting on the flop. This has traditionally been considered as bad play, hence the name “donk”.

Pluribus was in a position to donk bet 568 times and did it 11 times, so 1.9%. This is twice as much as the pros who did 1% of the times they had the opportunity to, but not huge either. Let’s look at every single one:

Every Pluribus Donk Bet in SRP

  • Strikingly, Pluribus has only donk bet in multiway pots. Interestingly Thomas Pinnock does mention multiway pots as one spot where donk bets “could” make sense as there is less a need to protect the checking range. This is because every player will need to be less agressive on the flop with lower equity.
  • If we’re donk betting, we need to protect that range. Pluribus here does 5 bets with very strong hands and 5 “bluffs” so it looks pretty balanced.
  • Maybe we can use this in live games that have many multiway pots with a decent frequency of value to bluff. We can’t go crazy on frequency, but Pluribus does it almost at 10% frequency (donk on multiway pots).
  • As with c betting, Pluribus varies bet sizes including some overbets.

Author: Yolanda Wade