The auction makes little sense to me. How does North know that one of south's two key cards is not the ACE of diamonds?
RHO can not have much for his 2
♦ bid.. ESPECIALLY given his partner LEAD the
♦ACE... That leaves him with, at most D-KQJ S-JACK, and C-Q as that is all that is unaccounted for. No doubt he had a preemptive hand, but at these colors just could not "afford" a jump to 3
♦. We can assume EAST will not have a spade void (no lightner double) and that EAST can not have five spades (since WEST with spade void would have raised diamonds), so spades are no worse than 4-1.
If spades split 3-2 or if LHO has 4 of them, you have 5
♠, 4
♥, 1
♦ ruff and 2
♣, so it looks like you need at the very least to ruff one more diamond. Three diamond ruffs would see you home with 3
♠, 3
♦ruff, 2
♣ and 4
♥ -- but you lack the entries to get three diamond ruff and return to you hnad to pull trumps.
Can you manage a 4-1
♠ split? 4
♠, 4
♥, 2
♦ ruff, and 2
♣ is is one trick short. The diamond ACE lead, however, has very likely isolated the diamond threat to RHO hand given the bidding. If we think RHO needed the
♣Q for his bid, we might think of a squeeze. Unfortunately, such a squeeze would have to be a vienna coupe (cash both club winners), and the manuever to establish the fourth spade (ruff one), will have removed the entry from dummy (spade ACE-KING) so the squeeze would fail for lack of entry. In fact there is no useful way to excercise such a squeeze even if you get spades correct for five tricks, because the entries are so muddled up. Assume, for instacne Heart ACE, Heart QUEEN, Heart Jack, S-AQT(success)K3, you end up with something like with lead in dummy.
So, you simply have to play for 3-2 hearts, and (gasp), LHO having four spades and three hearts.
Ruff lead. Cash Heart Queen, Heart ACE. Ace of spades, queen of spades -- RHO best show out and not ruff. If RHO follows, you will have to reconsider the line and play for club queen drop or club queen hook). Spade hook, spade throw away a club. AK of club, club ruffing finesse (ruff with the TOP heart, heart to dummy and claim. 4
♥ in dummy (one a ruff), 3
♣, 1
♣ ruff, 5
♠.
N E S W
1♠ 2♦ X P
4♦ P 4♥ P
4NT P 5♥ P
5NT P 7♥ P
P P