[themarc]

https://tinyurl.brid...se.com/44wuswxf

With 6 tricks left to play in a 3 Spade contract Ben claimed all the tricks even though there was still a trick to lose. After denying the claim and beginning to play it out, with 3 tricks left, partner robot Ben proceeds to throw away the Heart guard to keep two clubs, a suit I had bid twice thereby allowing declarer Ben to make good his invalid claim.

[johnu]

 kerkido, on 2026-May-15, 13:11, said:

It's a double squeeze - if both defenders throw a club to hold onto their red suit guards, dummy's clubs become good.

Exactly. If North keeps a heart and throws a club, East throws the losing heart. South must keep ♦J or else West's ♦10 is a winner. So South has to throw a club, and East scores the 13th trick with ♣4.

So, the double dummy analyzer worked perfectly in the end game.

But, what was the nonsense going on in the 2nd diamond trick. Why was ♦Q and not the ♦10 (or even ♦5) played by declarer after North had played ♦K under the ace on the first diamond trick?

[shyams]

 johnu, on 2026-May-15, 17:18, said:

But, what was the nonsense going on in the 2nd diamond trick. Why was ♦Q and not the ♦10 (or even ♦5) played by declarer after North had played ♦K under the ace on the first diamond trick?

I had previously posted a similar example (link: https://www.bridgeba...n-obvious-ruff/) where the bot refused to believe his partner had a singleton King at trick 1.

Given how this bot behaved identically (the minor diff being that it was a declarer bot), this may well be a programming issue / bug that needs to be addressed by the developer team.