Has partner lost it (again) ?

Your partner makes a slightly unusual opening lead.

What are your first thoughts:

1. Oh no! Not again!

2. Why can't my partner just play down the middle like a human being?

3. How long before I can get a drink?

4. What is partner trying to tell me?

Leading a card lower than the standard fourth best is a useful defensive device, not often discussed in the literature. In situations when you are known to have,  or partner can recognise, an original   holding of four higher cards, it can serve two purposes.

1. It can reveal extra length. A typical example is when you lead dummy's first bid suit. The lead of the deuce can be used to show four or six card length. Partner is more likely to be able to read this than declarer - in a way similar  to third & fifth leads.

2. It can act as a warning bell to partner that there is something unexpected about your hand.

3. It can draw attention to the lowest (remaining) suit.

Here was a nice example from the Wednesday duplicate (pairs scoring):

At favourable vulnerability, you hold as East: ♠75 ♥AJ5 ♦QJ52 ♣Q863 and the bidding proceeds

West	North	East	South
Pass	Pass	Pass	1♠
2♠(1)	Pass	2NT(2)	3♠
Pass	Pass	Pass (3)

 (1) Michael's cue-bid, showing hearts and a minor, usually 5-5 or better

 (2) Enquiring as to the minor. Maybe 3♥ would be a better choice....

 (3) ....allowing you now to bid 3NT, suggesting the option of competing in a minor suit

Against declarer's 3♠, partner leads the ♥2.  You can now see:

You know that partner would not lead low from a suit headed by the ten, so when the four is played from dummy you put in the knave, which holds the trick, declarer playing the three.

Partner has made a Michael's cuebid of 2♠ showing in principle 5 hearts and 5 cards in an unspecified minor, and so, looking at the dummy, you deduce that he holds diamonds as well as hearts. What do you lead at trick two?

Now what is going on here? Declarer must have six spades if not seven for his bid of 3♠, and one might reasonably assume that he has a singleton heart since partner's bidding invited you to bid 3♥ on a three card suit.  You could of course lead a spade, through declarer - but isn't that just doing his work for him? Perhaps a diamond to pin declarer's presumed king?

Wait - ask yourself again about that ♥2. Partner presumably holds ♥Q10962, so why did he not just lead the ♥10 or maybe ♥6?

Well, what if partner holds ♠Axx ♥Q10962 ♦K9xxx ♣void? You have one chance now to play a club and give partner his ruff, holding the contract to nine tricks.

And can a club possibly cost a trick on any reasonable layout consistent with the bidding?

However at the table, East led the ♦Q, declarer playing the ♦3 and West the ♦4. Again, it matters little what signalling method you are playing - attitude or count - partner has played his lowest diamond. Short of leaning across the table and pulling a card out of your hand, or kicking you under the table, there is little more that partner can do. For the sake of your partner's blood pressure, any lead now but a club is liable to require a subsequent call to the ambulance services.

The full layout: