Playing in a sectional tournament, we had a horrible first session (47%) and a great second session (60%) to average out at an okay 54%. Going back and looking at the near-zeroes in the first session, I notice that I got a couple of defenses wrong, and got suitably punished.
See if you would do better in the West seat.
Here is one board:
North is declaring 4S after partner (East) opened 2H and South doubled for takeout. I furthered the preempt by bidding 3H and North bid 4S.
East leads the 8 of hearts and after taking the Ace of hearts, what do you do?
At the table, I led back a club and N-S wrapped up 11 tricks. Holding 4 spades, I needed to be thinking about a forcing defense. I should lead back a heart (!) making South ruff once. Then, when declarer is pulling trumps, I should duck twice, take the third spade and lead another heart, forcing North to ruff. At that point then, South will have give me another spade trick.
Most of the field was not in 4S, so holding them to 4S would still have been below average, but as it was, letting them make 5S was a bottom.
This was the second defensive board I didn't get right:
North opened 1C, partner doubled for takeout and N-S had a tortured auction to 2S (North bid 1C, East doubled, South bid 1S, North bid 2C, South bid 2D and North bid 2S, all-pass).
Sitting West, what do you lead?
At the table, I thought I needed to cut down on ruffs and led a spade.
This is bad for several reasons: one is that my clubs and partner's diamonds are in finessing positions, so declarer doesn't need ruffs. Second, the auction implies a 4-3 fit, and so partner has 4 spades. I need to lead the 10 of hearts so we can take our tricks, and let declarer navigate the bad split with no throw-in suit.
Both of these hard to defend, but I had the clues in the auction to make the right lead at the table.