This hand came up on BBO.
You are playing with a robot. The robot says that the 2NT bid shows 8-11 HCP with no five card major.
With a good 24 count plus a good 5 card suit, you want to be in slam no matter what. With a robot partner, bidding to the right grand slam seems a little iffy. Therefore you bid 6NT, all pass.
The lead is the ♠6.
Since dummy is a robot, you will swing over to the South seat and play it. South plays all the hands, right?
Prospects look good. In top tricks you have two spades, three hearts, one diamond, and four clubs for 10 top tricks. Diamonds, spades, and clubs combined need to provide two more.
In the robot game you want to make the hand, and if possible make an overtrick.
You can set up one trick by force in either diamonds or spades. But, if the ♦K is onside, you can make an extra trick in diamonds without losing one. So, given a choice, it seems like you might prefer to play diamonds.
At trick 1 you play the ♠K. Nicely done. What's next?
Clubs will be 5-1 or 6-0 about 16% of the time. Don't neglect this possibility!
If clubs don't split, can you still make the hand? Before playing at trick 1, decide whether you must have the clubs 4-2 or not.
Your hand has three entries: the ♥AQ and the ♣J. You should make good use of them. So test the clubs by playing the ♣A and a club to the jack!
Aha! The clubs are 5-1!
You are now in your hand thanks to the ♣J entry. Make use of it by taking the diamond finesse. If the diamond finesse loses, you will need diamonds 3-3 or doubleton ♠Q.
If the diamond finesse wins, you are now 100% to make the contract. How? Simply unblock the ♠A, return to hand with a heart, and play the ♠J discarding dummy's club loser. They can win their ♠Q but you return to your hand with the other heart entry and play the ♠T discarding dummy's diamond loser. Now dummy is high.
Here's how the play would go if the diamond finesse wins.
Do you see how vital all of the entries to the South hand are?
This hand will catch many players in a complacency trap. Clubs are splitting 84% of the time. But on this hand, if you play ♣J and then ♣A, you will burn an important entry.
Yes, you can still make the hand as the cards lie. But on other layouts, you would go down in a cold contract.
Don't count on a suit splitting normally if you don't have to! If your side suit splits badly, try to find another line that will work.
Plus... it's free!