[super69]

I'm here to ask if I did something to deceive GIB on the defense of this hand, or if it made a clear error.

I led the ♠K at trick 11 in hope that partner was still in possession of ♠QTx, which would allow us to take 2 of the last 3 tricks. Even though partner did not have the holding I was wishing for, isn't it clear to play the ♠Q at trick 12 to set the contract or did my play "deceive" GIB?

http://tinyurl.com/ynv6rg6k

[smerriman]

Am I correct that this was MPs, rather than IMPs?

It does not take anything about whether you should / shouldn't have played a certain card in the past into account, so it was not deceived in that sense.

However, it also doesn't assume anything about declarer's line of play either; it just considers all of the possible holdings you might have.

If you had S9H8 or S7H9 (or both hearts, though we can probably rule that out from the bidding), it doesn't matter what it plays - the contract is down 1 both ways.

If you had S7H8 (like you did), Q beats the contract by 1, while low lets the contract make.

But if you held the just as likely S9H9, the contract goes down an extra trick if it plays low.

And it also goes down an extra trick if you held both remaining spades.

So it should comfortably play the Q at IMPs, but I would expect it to play low at MPs.

[super69]

It was MP. Your explanation makes sense, thanks very much.