Interesting you should mention a club switch. One declarer tried the following; 1. Win spade lead. 2. Run Q♦ 3. Duck spade return. 4. Win spade continuation. 5. Cross to A♦ All those who got a spade lead played as above...now this declarer diverged. Instead of running diamonds, she took the view that A♣ was the same 50% as K♥, but with an extra chance... 6.Played a small club to Q, which held. (South cannot go up A♣, or it's game over.) 7.Cashed three remaining diamonds. 8.Played a club to the K and South was end-played. She lost one spade, K♦, and two clubs. Is this a good line? Of course, if South had only clubs, they're cashing them and you're down. But, West took the view that suits were behaving. D.