The bidding: North has 14 high card points and a balanced hand. He does not enough for opening one notrump, so he opens his better minor, one club. South jumps to two notrump showing a limit raise and stoppers in the unbid suits with no skipped four-card suit. If South had a four card suit besides clubs, he would bid it at the one-level.
South has five card or longer club support, so he could have given a minor limit raise, but he wants the lead for his two doubleton kings. If he had a suit without a stopper, he would have made a limit raise in clubs. Three clubs over one club is a limit raise in clubs and shows 10 to 12 points with at least one side suit without a stopper, no four-card major (diamonds too), and five-card support.
Length Points: One counts shortness points when the partnership has found a golden fit (a trump suit with eight total cards or better). However, one can count length points if one is responding or reevaluating one’s opener. The fifth and sixth card in a suit is worth a point. The seventh is usually worth 3 points. There is a proviso which some people forget. The suit must be accessible. There must be a side entry or sufficient support from partner. A five card suit headed by the jack or queen is probably not worth a length point.
The Lead: West is going to lead a major suit because of the bidding. Neither opponent has shown a major. There is a rule of thumb that when one has two equal length majors, one leads the one that needs less help from partner. West leads the heart ten. He needs partner to have the jack, ace or king to avoid giving a trick away. In spades, he needs partner to have the ace or queen.
The play: East wins the opening lead with the ace of hearts and returns his original fourth best card. South wins the king. He cannot lose the lead in case the opponents can cash enough hearts.
He cashes six clubs and watches the opponents’ discards. If they each discard a heart, South may take the diamond finesse. East discards two spades, a heart, and a diamond. West discards a spade, no hearts, and four diamonds. East is guarding the queen of diamonds, so the diamond finesse is not taken.
Declarer cashes the king of diamonds and West pitches a spade. If he exits a spade, West will win the blanked ace (an ace made a singleton because of discards) and then return a heart to West. West will cash the king of spades and two hearts. The defense will get three hearts and two spades for down one.
Instead, South cashes his six clubs and two diamonds and comes to nine tricks to make 3NT for +400 points.