Was a bridge column "resulting" when it criticized an opening lead?

Both sides vulnerable, South dealt and bid one heart. West overcalled one spade, North three hearts, East three spades, South four hearts, East four spades, South five hearts.

West held (s) KQJT8 (h) 2 (d) K93 (c) JT32, and led the K of spades. The column characterized the lead as "natural," but called it an error, because leading the 3 of diamonds would have beaten the contract. (East had the A, West the K, and East a "side" trick.) In the actual hand, South captured the K of spades with the A, and then successfully "sluffed" two diamond losers).

Is there any widely accepted theory or statistical study (e.g. a Monte Carlo simulation) that would lead one to believe that the 3 of diamonds is the better lead a priori, based on the bidding? Or am I right to believe that the columnist was "resulting," based on this one hand?

If the lead of the 3 of diamonds was statistically inferior, but made by an expert, would it just be considered a mistake, on would it be grounds for potential discipline, based on the assumption that the expert had more knowledge of the hand that he was entitled to?

• Did North (Dummy) come down with something like x-Jxxxx-xx-KQxxx, and Declarer perhaps xx-AKQxx-xx-Axx? That would leave partner with Axxxx-xx-AQxxx-x and Declarer with a fast diamond pitch if we don't lead it Commented Sep 28, 2015 at 10:57
• It would also have been REALLY useful to know what LHO denied by not bidding 2S - it leaves me wildly guessing as to what specifically 3H meant and showed. Commented Sep 28, 2015 at 11:08
• @ Pieter Geerkins: West had five spades, East had four, hence their bids. With a "solid" five card spade holding, West might have bid two spades, (treating them as six, per Marty Bergen) but didn't. I'd bid two spades with KQJTx, but one spade with KQJxx and the rest of West's hand. Commented Sep 28, 2015 at 13:24
• @Aryabhata: The hand is here: baronbarclay.com/product/bridgecolumn092415/September2015 Commented Sep 28, 2015 at 21:31
• @TomAu: Now that I read the article, I don't see the claim anywhere that a spade lead was an error. I believe the error referred to was by East: not underleading a diamond for a trump promotion (4th club from West, and East makes the trump Jack). The error south made was not making a scissors coup (play 4th club and throw the other diamond loser). Those are the errors that cancelled out. There is no resulting about the opening lead. Commented Sep 28, 2015 at 21:39

1. Yes, it would have been resulting had it criticized the opening lead. As @PieterGeerkens noted, the article neither terms the lead an error nor implies it.

2. Thanks, @Aryabhata, for posting a link to the actual column.

• I "second" your second comment. Thanks to Aryabhata for showing me it could be done. Next time I'll do that. Commented Sep 30, 2015 at 21:38
• It was actually Pieter who posted the link. Commented Oct 1, 2015 at 20:48

Second question first: Could this be evidence of cheating?

Not by itself. A large number of hands where an expert correctly guessed along with a paucity of hands where the expert incorrectly guessed might be considered evidence of cheating. This kind of thing comes up in maybe once in a hundred deals, the case where the lead makes a difference maybe once in five hundred, and I would think you need at least a 5/5 or 9/10 success rate to even think cheating might be going on. We're talking about looking at 5,000 deals, and pretty much only professionals play that much bridge in a year.

First question: Is this really an error?

It really depends on how likely one of the opponents is to have a first round spade control (ace, void, or both) and a source of discards (both ace and void, or running clubs). This in turn depends on their bidding system and style. For example, South was limited to say 15 points (playing some strong club system), it would be much more likely. Also if North was by agreement very weak (say <6 points) for the 3 hearts bid. It's also possible South has a lead directing bid available over 4 spades (say if 5 diamonds would have meant "I want to play in 5 hearts but if they bid 5 spades then lead a diamond"), in which case failure to make such a bid is meaningful. Also, West might have information from opponents' mannerisms that West is certainly allowed to take advantage of.

Unless it's actually clear one way or the other (I'm not an expert; I don't know), it would be pretty hard to make enough justifiable assumptions to say what the right play was.

Also, if it's a long team match, there may be state of the match considerations about how much of a risk you want to take.

• Now that we have learned 3H was actually an invitational (or maybe even game forcing) raise rather than a pre-emptive one, I am much more in favor of a diamond lead. But I will leave this whole response up. Commented Sep 28, 2015 at 22:20