[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.

[kerkido]

Ben's claim was valid, and very nice play - at that point the overtrick was 100% cold on any defence.

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

It's clear to North it makes no difference what it discards (if South has the club King, you're taking the last two tricks regardless).

[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.