No Trump contracts on the hand detailed above made 11 or 12 tricks by North and South depending on the lead. Nearly all pairs opened their strongest bid 2♣ or 2♦ and one pair of brave (?) souls finally ventured 6NT but were defeated by the A♠ lead and a Heart switch.
The pair that benefited most had a bid in their armoury to get to the best contract. After an opening 2♣ by South, North with a fair balanced positive bid (at least an Ace and a King, or three Kings)chose to bid 2♦ as either a Negative bid or possible "Waiting Bid". South was now able to confirm his Diamond suit with 3♦. North set the suit with 4♦ and South advanced with a fine cue bid of 5♣, suggesting a Diamond slam, not forcing to one! Note that this cue bid denied the Aces of ♥s and ♠s but showed at least something "very nice" in both suits that had been bypassed.
Holding the A♥, North, thinking that South may have a possible singleton in ♥ and at least the K or KQ in Spades, now chose to give nothing more away and bid a simple 6♦. East led the ♦10 but slam was cold on any lead.
North won in Dummy, drew trumps, led a ♥ to the Ace and played a ♠ towards the K in dummy, which held. Now able to lead a ♣ to the K and play another ♠ towards Q, East took his Ace and 12 tricks were there. Note, if East ducked the ♠ a second time, North could make 13 tricks by ruffing ♠s with his remaining small ♦s.
6♦ making gave N/S all the match points for an outright top. Also, North got to play with one of the weakest suits you can hold as trumps!
Tip - 7 CONSIDER USING 2♦ AS EITHER A NEGATIVE BID OR A "WAITING BID". This can be shown with your second bid. Here when North raises Diamonds he must have a positive.