Here are the reasons to lead trump –
1). The opponents have bid all four suits and end up in 4 spades –
— the logic is that you will be giving away a trick. BY leading trump, you keep the declarer guessing where the high cards she is missing are located. Make declarer lead the suit!
2). The opponents stole your contract. You figured out – between you and partner you have 25 points and could make 4 spades vulnerable – the opponents overbid to 5 clubs (not vulnerable) —- and are sacrificing! Double their 5 clubs for PENALTY and THE MOST IMPORTANT THING YOU HAVE TO DO IS Lead trump (YOU AND YOUR PARTNER) at every opportunity.!! Once their trump are off the board they will not be able to ruff your high cards.
3.). Declarer is playing in her 2nd bid suit –
Opened – N bids 1 spade – S bids 2 clubs
N bids 2 diamonds and South passes
N is playing in 2 diamonds and has 5 spades she will want to trump in dummy. South does not have more than 2 spades or the contract would have been in spades. Take out Declarer’s trump!!!! She will be planning on trumping those spades in Dummy!
4.). Declarer does not have an 8 card (magic fit) –
N bid 1 spade and S responded 1 NT
N rebids 2 clubs and S chooses spades over clubs! S is a minimum responding hand and N has an unbalanced hand with 5 spades and possibly 5 clubs – South has at least 2 spades as she did not initially respond 2 spades! Lead trump so N cannot use dummy’s two spades.
5.). Dummy goes down and there is a singleton trump on the board — lead trump your first opportunity!!!!
6. Dummy goes down and you see a short suit for which you have high honours or your partner may have bid during the auction, now it’s time to switch to leading trump!
They used to say “LEAD TRUMP WHEN IN DOUBT ABOUT WHAT SUIT TO PICK ”
Now, when you lead trump you will have a valid reason.
Your opponents will start to tremble when you are their opponent!