Why does your partner lead up to dummy’s strong suit, instead of to the weak one? He is probably leading a singleton, or he may be very long in that suit and hopes that you will trump.
Why does the dealer not lead trumps? He may be trying to establish a “ruff” in the weak hand; he may be trying to arrange the lead so that his trumps can be led advantageously from the weak hand; or it may be because the balance of trump strength is against him.
Why does your partner abandon his long suit against a “no-trump” make? It is because his card of re-entry has been taken out, because the suit is hopelessly against him, or because he is waiting for you to lead through the dealer’s hand.
Why does your partner refuse to return your lead in a “no-trump” hand? It is either because he has no more of your suit, or because he considers that his suit is stronger.
Why does your partner immediately return your lead against a declared trump, instead of showing his own suit, or leading up to dummy’s weakness? He is evidently anxious to trump the third round of your suit.
With a “no-trump” hand, why does the dealer part with the ace of his adversaries’ suit on the first round? It is because he has that suit protected, because he can see enough tricks to win the game, or because he is afraid that some other suit may be made against him.
After you have led up to the weak suit in dummy, and your partner has taken the trick cheaply, why is it that he does not return that suit? He is evidently waiting for you to lead through the dealer’s hand.
If, against a “no-trump” declaration, you are in doubt as to the location of the winning card in your own suit, notice the card that your partner plays in returning your lead, and remember that he will return his highest card. This will enable you to tell what higher cards are in dealer’s hand.
If you lead a high card, against a “no-trump” make, notice the card that your partner plays to the trick. If he has four or more of that suit, he will not play his lowest.
If the dealer takes out the commanding trump, he is either trying to make you lead up to high cards in his hand, or some long suit is established against you. If it is for the latter reason, be cautious about forcing him. Make what you can in the remaining suit. It may be dangerous to lose the lead.