Pass - Pass - Pass: West opens 1NT and east responds 2S
Acol Bidding
Pass - Pass - Pass: West opens 1C partner overcalls 1D and east responds 1S. Support partner with 8 points and a 4 card diamond suit.
Plan Before You Play
You end up in diamonds and there is a spade lead. Count your losers. Two in spades, 3 in hearts, none in diamonds and 1 in clubs. Plan your play To minimise tricks lost you will need the opposition to lead the club suit to set up a finessing situation for you, so your plan is to draw trumps ruff the third spade lead and discard a small heart in the short hand so that you can ruff the third round of hearts
The Play
Lose the first 2 spade leads. Play low on the club switch and cover the KC. Draw 2 rounds of trumps ending up in hand lead the 10C club cover the JC now the 9C is good. If the opposition switch back to spades you can ruff a spade while discarding a low heart so there are only 2 heart losers, but if they switch to the heart suit and play three in a row you are only able to make 8 tricks.
Comment
In 2S making 2 East-West gain 110 points. Forcing them to bid by competing up to 3S earns your side 100 points. If you bid 4D going only 1 light the opposition earn only 50 points. The trick to taking 3S light is to lead diamonds and the heart suit leading through strength
The above commentary is intended as a guideline only. As with any Bridge hand there are many ways to bid and play any hand.