Came up with this problem today, please enjoy :) [hv=pc=n&s=sa3h74dakq3cakq82&w=skjt86hqjt9d74c73&n=sq975hak852d95c96&e=s42h63djt862cjt54]399|300[/hv] 1. Make 4 spades on the lead of the ♦7 2. Find all 4 pairs of consecutive cards (two cards that are one apart from value in the same suit, such as a ♠10 and a ♠jack) that, when switched, makes the contract unmakeable against best defense. For example, if one switched the ♥KQ, giving north the ♥Q and west the ♥K, but this does not defeat the contract. Don't open the spoiler until you figure out problem 2. just for kicks: 4. Defeat 5♥ in the south.