Demonstration, Part 3

Demonstration, Part 3

N
W   E
 
S
♠ K 8 6 5
♥ A 9 7 3
♦ Q 8 5
♣ 6 5

Dealer:

West

W N E S
1♣ 1♦ 1♥ 3♦
Pass Pass ?

Look what happens if we respond 1♥ on the first round.

We must pass 3♦. We are not strong enough for anything else, and have no known fit with partner.

Afterwards we discover that we had a spade fit. What went wrong?