humm... Lets try an average (more or less) holding for each suit: - pd holds 6 spades to the King > we have 6 tricks (over 90% of the times) - pd holds 6 Hearts to the KIng > we might have 5 (49%), 4 (18%) or even 3 (well, do the math...) Moreover, if we hold 6 spades, pd is more favorite to be short in Hearts, which has the potential do diminish our losers in that suit. If he holds 6 hearts, he is more favorite to be short in spades potentially diminishing our holding in that suit.