Jeff and I were playing against Izzy and Pamela Nisbet (Izzy's new partner) and this nice bidding sequence came up.  First, the hands:

1st seat

A75 / 4 / AKQJT8 / AJ8

3rd seat

KQT6 / 9875 / 7432 / 7

I opened 1 Diamond in first seat (pretty normal, you're not good enough for 2 Clubs, especially since your suit is a minor.)  Jeff bid 1 Heart (arguably he might have bid 1 Spade, especially since we play Walsh style, but 1 Heart is normal.)  Now what?

I was torn between 2 Spades and 3 Clubs.  2 Spades is cheaper, but it might be harder to talk partner out of playing in Spades than to talk partner out of playing in Clubs.  I eventually decided that saving room would take precedence.  2 Spades it was.

Here's where Jeff made a thoughtful bid.  I'm a little torn about 'thoughtful' bids because often in an attempt to avoid problems A, B & C you generate problems X, Y & Z that you just hadn't thought of.  I'd have bid 4 Spades with Jeff's hand.  We've arrived.  But Jeff chose to cut me some slack and bid 3-only Spades, just in case I'd manufactured a 2 Spade bid.

Now I bid 3NT and Jeff was back in the spotlight.

He knows I don't have 4 Spades, so I must have at least 6 Diamonds.  I surely have at least 3 Spades and 6 Diamonds and he has all his values in Spades and 4 card Diamond support.  I also might be counting on him for a Heart stopper in NT (since that's the first suit he bid.)  He made the excellent call (I doubt I would have found it, but this time I think it's definitely the RIGHT bid) of 5 Diamonds.

Back to my hand, Jeff's bid Hearts and Spades and Diamonds.  Guess how many Clubs he has?  The minimum 'perfecta' hand I needed is exactly what Jeff had.  I bid 6 Diamonds. +1390 (Club lead) was worth almost 13 IMPs.  One other pair was in slam (2NT - P - 3C - 3H - 6D is not an auction I'm particularly interested in duplicating.  It did have the added benefit of getting doubled.)