'The most interesting questions from visitors to the Dutch sister site (Bridgevaria.nl)'. 

Dear Ed & Peter,

Declarer orders a small trump to be played from South. West has the trump jack and one small trump.
In my opinion West should play that small trump ('second hand low'!).
My partner disagrees; he thinks West should play the jack.

 Answer Ed Hoogenkamp (South)

Dear Dorus,

The amount of information you give is minimal. Without knowing anymore details I agree with you. The natural card to play in the second hand is indeed a small one (in virtual all countries outside Norway), when declarer begins with a small card. Inserting the jack would simply cost a trick in the following situation:

		♠	A 10 6 2
♠	J 7			♠	Q 5 3
		♠	K 9 8 4

South starts with the ♠4. Suppose West plays the ♠J. North wins with the ♠A, after which declarer can finesse for East's ♠Q. This way he does not lose a single trick.
If West plays the small spade to the first trick, declarer is certain to lose a trick.

There are situations however in which inserting the jack doesn't hurt.

		♠	A K 10 2
♠	J 7			♠	??
		♠	??

South advances the ♠4 and West can try the effect of playing the ♠J. Usually it will not have any effect apart from giving declarer the false impression of a bad trump split (especially if NS have a 4-4 trump fit, this might put declarer on the wrong track).
Having said that, I remember this case from a club evening at Bridge Club 'De Kaag'.

		♠	A K 10 2
♠	J 7			♠	Q 8
		♠	9 6 5 4 3

This was the trump suit. South played a small spade and West inserted the ♠J. Declarer won in dummy and crossed to his hand in a side suit. He played another small spade from South and when West produced the ♠7 declarer finessed!
'Restricted choice', he explained...

By the way, did your partner explain why he thought West should play the jack?

Un saludo, regards from Barcelona

Answer Peter van der Linden (North)

Dear Dorus,

I agree with Ed that you give us too little information.
Still, something struck me in your question (not so Ed of course, probably he forgot to put on his reading glasses — again). You wrote that declarer ordered a small trump to be played from South. So South is dummy and the problem hand, with Jx, is behind South.
All of Ed's examples show the problem hand to be before dummy. Oh well, too much sangria and paella.

In order to enhance readability I rotate your problem by 180 degrees, so dummy moves from South to North (it is usual to put dummy North) and the problem hand from West to East.
This is your problem, therefore: declarer plays a small spade (trump) from dummy and East is to play:

		♠	.....
♠	??			♠	J x
		♠	??

Well, I suppose that now you see which information you omitted to send: what is dummy's trump suit?
I can imagine only one situation in which I would play the jack:

		♠	A K Q 3
♠	??			♠	J 5
		♠	??

If declarer were to play the ♠3 from dummy, I would play the ♠J...
Not so Ed, it's far too hot in Barcelona to mastermind such a play.

Alright, a somewhat more serious example:

		♠	K Q 7 4 3
♠	??			♠	J 5
		♠	??

If declarer were to play the ♠3 from dummy, I would play the ♠J if I suspected my partner, West, to have the ♠A and that declarer lacks an entry in his hand, needed to play towards the ♠KQ. After all, a clever South player might venture playing a small spade towards the ♠10x in his hand.

But usually the second hand plays low in this kind of situations.
Only if East has two touching honours, it is sometimes correct to 'split his honours' (insert one of his honours):

		♠	K 7 4 3
♠	??			♠	Q J 5
		♠	??

If declarer plays the ♠3 from dummy, inserting the ♠J is sound play, in case South has something like ♠A1092: if East were to play the ♠5, South might play the ♠9...

Still, splitting his honours can turn out wrong for East. The longer his own and dummy's suit, the bigger the chance it backfires:

		♠	K 7 4 3
♠	10			♠	Q J 5 2
		♠	A 9 8 6

It will be obvious that East will regret playing an honour on dummy's ♠3 (remember: he cannot see the West and South hands).
So even if East has two honours, he should not automatically play one.
This is all the more valid if dummy doesn't have an honour:

		♠	7 4 3
♠	10 8 6			♠	K Q 2
		♠	A J 9 5

If declarer plays the ♠3 from dummy and East splits his honours, South will win, cross to dummy and play the ♠4 to the ♠J.
If East plays the ♠2 on dummy's ♠3 (first spade trick), South will probably try the ♠9, since this is winning if East has the ♠K and the ♠10 or the ♠Q and the ♠10, while finessing with the ♠J at the first spade trick will only win if East has the ♠K and the ♠Q.
Note that this situation is easier for the defenders if the ♠AJ9x are visible, in dummy:

		♠	A J 9 5
♠	K Q 2			♠	10 8 6
		♠	7 4 3

If South begins with a small spade, many West players will play a small one.
Many of these players would however, if they were East in the previous diagram, split their honours.
Let's change the layout a bit:

		♠	A J 9 5
♠	K 10 2			♠	Q 8 6
		♠	7 4 3

South begins with a small spade. If West plays a small one, the average declarer will insert the ♠9, as we have seen.
So a clever West player may try the effect of playing the ♠K to the first spade trick, suggesting he has ♠KQx(x). But a clever declarer has seen this before and doesn't fall for this. So he finesses the ♠9 the next round anyway!
So at the first spade trick a clever West player may next time play low again from ♠K10x/♠Q10x and old-fashionedly split his honours if he has ♠KQx... But a clever declarer...
All right, we've ended up in a case of ladder psychology.

To conclude with an example from practical play. Ed played two little old ladies. In bridge parlance a little old lady used to be known as lol, but nowadays this acronym is used for something different, so my children tell me. Anyway, it happened in Spain, so let's call them little old señoras. This was the trump suit as Ed, who was West, saw it:

		♠	K 9 3
♠	Q J 2			♠	??
		♠	??

Against 4♠ Ed led a heart, won in dummy. Little old señora South crossed to her hand with a diamond and played the ♠10. Of course Ed covered but he quickly came to regret this, since little old señora South ducked in dummy!

		♠	K 9 3
♠	Q J 2			♠	A
		♠	10 8 7 6 5 4

East, Ed's future ex-partner, had to overtake with the ♠A and later little old señora South successfully finessed for Ed's other honour.
Little old señora South's handling of the trump suit was necessary to make the contract, since she turned out to have two unavoidable losers outside the trump suit!

What we can learn from this:
1. If a defender has only one honour, he should usually not play it in the second hand, unless he can make the trick by doing so.
2. With king-queen or queen-jack he will often split his honours in the second hand but by no means should he do so automatically. Dummy's holding in that suit and the bidding often suggest that he play a small one.
3. If Ed is playing little old ladies: put your money on the little old ladies.

En hils, regards from Orkanger