This deal comes from a 2012 Florida Regional knockout event. My long-time bridge partner, David Berkowitz, held this South hand:

AKJ965
Q65
A
AK5
Playing Precision (with his current partner, Alan Sontag) he opened with a Strong Club. I'll get back to his contract later, but let's try this hand in Standard. If you open 2, partner responds 2 waiting. RHO overcalls 3 and you bid 3. Partner bids 4. For better or worse, you guess to raise to 5 and partner carries on to a club slam. Hopefully, he has hearts under control.  In the Berkowitz auction, he also faced a heart preempt from RHO and ended in 6.  This is a lead-out-of-turn auction, but of course, in both auctions described, the big hand is the declarer. A low heart is led and you see:

102 2 K742 QJ10932

AKJ965 Q65 A AK5

Partner has great trumps and the desired heart control. This looks fairly easy. RHO wins the K and shifts to the 8. Over to you.

How about winning the A and drawing trumps? If you do, West has 3 clubs and East has one. Then, you play another spade. If RHO shows out, you go up with K and have a marked ruffing finesse against the Q--with the A to get back to hand.  What if East follows low to the second spade? Then, you go up with the K and as they are 3-2, you ruff to set up the suit.

So, what can go wrong? A look at the full deal shows you that East's 8 was a sneaky play:

Vul: N-S Dlr: S	102 2 K742 QJ10932
7 987 Q109853 876		Q843 AKJ1043 J6 4
	AKJ965 Q65 A AK5

East won the K and shifted to the 8 at trick two--a nice deceptive play. Assume you draw trumps and play another spade from dummy. You'd have no way of knowing to finesse, so would go up on the 2nd spade. There is no recovery. You can no longer set up the spades (you have only one entry left to hand). Down you'd go.

There was a better and safer line of play. Berkowitz, not wishing to rely on the spades, won the A at trick two, but didn't draw trump. He cashed the A, ruffed a heart, ruffed a low diamond from dummy high in hand, ruffed his last heart and ruffed another low diamond high in hand. Now, he played his low trump to dummy's high clubs, drew trump and claimed.  In effect, he played dummy's two low diamond losers and ruffed them with the AK. After drawing trumps, there was no need to rely on the spade suit. Why trust a potentially sneaky opponent if you don't have to?