How do you bid this hand sitting in third seat after partner opens 1C and RHO passes?
The standard response would be to bid your four card spade suit. However, there are sound reasons that mitigate against this in favor of a 1N response. That sounds like heresy to most bridge players, since they are generally trying to find a major suit fit. However, when both hands have a 4-3-3-3 distribution, it is often better to play in No Trump even though you might have a 4-4 fit in a major suit.
Another reason to bid no Trump with this hand is that you have stoppers in all four suits. If you respond one spade it's likely your partner's rebid will be one no Trump, so she will be playing the hand if you go to three no Trump, which is probably the only reasonable game contract for this since you don't have a 4-4 fit in spades. And that's what happened with this hand. This hand responded 1S, partner responded 1NT and this hand jumped to 3N, resulting in big trouble because declarer did not have diamonds stopped. If you bid No Trump, you'll be playing the contract in 3NT, your LHO will be on lead, leading into you. A diamond lead cannot hurt you. Here are the four hands:
♠ KJ72 ♠ AT5
♥ Q97 ♥ AKT8
♦ K98 ♦ 763
♣ AJ5 ♣ Q98
West North East South
1S P 1N P
3N P P P
Opening lead: QD
You are playing East in 3N. How do you play against the QD lead? Assuming opponents are playing standard leads, the Queen could be from one of two holdings: QJT(x,x) or AQJx(x). You've got three diamonds on the board. If the lead is the second holding, the King will take the trick. If it's from the first holding North has the ace and if you play the King you'll lose your stopper. What to do?
The way this should be played is that you duck the first trick. However, when the Queen holds and South follows with the Jack, you must go up with the King. The reason is that if you duck this and South wins and was leading from AQJ he will then play the ace, capturing your King and you lose the first five tricks. However, all is not lost if you play the King on the second lead and North takes it with the ace, because the odds are that if South started with five diamonds, North only has two and will not be able to return a diamond to South's hand for her to take her remaining three tricks. So you duck the first lead and go up with the second lead, which takes the trick.
Now the hand is pretty much cold. You've lost two tricks, but you've got three hearts, two spades, and a club, along with your diamond. That's seven tricks. You can afford to lose two more. When you lead your second heart and discover that South had a singleton, you can then finesse North's Jack and take four heart tricks. You have two finesses you can try, spades and clubs. You clearly cannot take a finesse into South and take the risk that it loses, because South will then set the contract by taking the rest of his diamonds. So you take the club finesse and it loses. That gives you a second club trick. So you end up taking four hearts, at least two spades, two clubs, and a diamond, making your contract.
However, if West bids this correctly and disdains responding with her four card spade suit, responding 3N instead of 1S, the hand is much easier because the lead will be into her, with stoppers in all four suits. Also, as the hands lie, she'll get a spade lead, which will give her a third spade trick without having to take a finesse. She will never have to touch the diamonds.
Alas, there is a big problem with responding 1N instead of 1S. Partner may pass your 1N bid. So, to avoid this, since you have 13 high card points, you must just jump immediately to 3N, avoiding the possibility of partner passing out the hand when you should be in game.
So there are two lessons here:
1. If partner opens a minor suit and your distribution is 4-3-3-3 with a four card major and you have a game forcing hand with stoppers and all suits, bypass your four card major and respond 3N.
2. When declaring in No Trump, if the opening lead is a Queen through Kxx on the board, duck the first round and go up with the King on the second lead of the Jack.