Does the Liar's Dice AI cheat, or is it just irrational?

[Natty La Ridge]

I'm neither a Liar's Dice expert nor a statistician, but I understand dice odds well enough that I've maintained a better-than-average rating on FIBS for decades. That said, I'm having trouble figuring out whether there's a rational basis for the AI player's bids.

Fifth round of a match, AI's turn. Six dice in play, four mine, AI two. The AI's opening bid is three 1's. The odds of there being three of any face with six dice in play is 6.2%, so relatively low. If the AI has one 1, it's betting that I have two or more (13.2%). If it has two 1's, it's betting that I have one or more (51.8%).

Peeking under my cup, it just so happens that I have three 1's, exactly what the AI just bid. What a coincidence!

Assuming the AI is simulating a rational player (someone holding at least one 1), I counterbid four 1's. The AI comes back with a bid of five 1's. As unlikely as it seems with only six dice in play, five 1's is the only scenario where the AI's original bid makes statistical sense, i.e. is more than 50% likely to be correct. So I gulp and click Spot On. And it turns out...

The AI was holding a 1 and 5. So its original bid of three 1's was based on a 13.2% probability that I was holding snakeeyes.

It doesn't make sense to me that any rational player would bet on their opponent holding doubles of any face, with only four dice. That the AI should bet this way, when it just so happens that I'm holding three dice with that face value, strains credulity.

Maybe there's something I'm missing here, but the AI isn't a human player, so much of the art of bluffing doesn't apply. Is it just pulling bid numbers out of the air, or is it biased to bid on faces that it somehow "knows" I'm holding one or more of (which is to say, it cheats)?

[Natty La Ridge]

Followup: at the conclusion of this match, with two dice on the board, the AI bid three 1's. So the answer to my question is, irrational (buggy).

[Donkey]

I haven't seen the AI bid a higher number than available dice. I have seen the AI guess a higher number than it would know (for example, I have 2 dice it has 1 die - which let's say is a 5 - and the AI guesses 3 x 2s ... obviously wrong). I have considered this a "gimme."

[Natty La Ridge]

A "gimme" it may be. But I've concluded that the game cheats, that is, the AI player's guess is informed by knowledge of what's under the human player's cup. There are too many spot-on guesses of doubles, for example, when the AI player holds no dice with that face value.

I'm disappointed. I'd prefer a true RNG minigame to this.