The difference between pairs and teams is quite clear cut. At teams, borderline game decisions should be resolved in favour of bidding game even if it seems aggressive. South’s 1S bid is natural ( 2S would be fourth suit forcing). North, who might have invited, just bid the game and West led the 2H to East’s ace. Cover the South and West hands and decide what you would lead at trick two.
At the table, East supinely returned a heart and now West has no winning option. If a spade is returned to the ace and another is returned, South must carefully win it on table. Winning it with the 8S in hand leaves you in the wrong hand to set up the long club! Now cash one high heart, two high clubs and then ruff clubs and diamonds until the clubs set up. The last trump can then be drawn and dummy’s JH and last club can be cashed. It’s a little lucky but the diamonds cannot be set up so declarer shouldn’t go wrong. Can you see where the defence went wrong?
Teams, EW vul, Dealer North
There were two problems: the defence set up the queen and jack of heart for declarer and allowed him to set up the clubs. The best defence needs the first two tricks to be the AH and AS and then a spade must be led to the third trick and now declarer is off no matter how he wriggles. At first sight, this is surprising since the second heart loser vanishes on the AC but declarer cannot set up the diamonds or get rid of the heart loser.
Should West find the trump lead? Sometimes, with a singleton trump you will pick up partner’s queen but there is another consideration. Both declarer and dummy have shown an unsupported suit before agreeing on a third suit. This is often an indicator that a trump lead is necessary as here. A more common case is when one player uses an unusual 2NT and the other declares in a minor. The 2NT bidder is short in both majors and declarer is often short in the other minor making the trump lead an attractive attempt to reduce ruffing.