You receive the opening lead of ♥6, you win with the ♥J as East contributes the ♥2. Plan the play at IMPs as well as Matchpoints.

Solution:
At IMPs, where overtricks are totally unimportant, you would knock out the ♥A and claim 12 tricks. At matchpoints, you should consider prospects for scoring all 13 tricks.

If diamonds are 3-3, or if the spade finesse works, you can take all the tricks. Diamonds dividing 3-3 is a 36% proposition. In the remaining 64% of situations, the spade finesse will work 50% of the time, i.e. when diamonds are not 3-3, the spade finesse offers and additional 32%.

There exist squeeze chances as well. If East holds the ♠K along with length in diamonds, he could be squeezed in three suits - spades, diamonds, and hearts (he needs to retain a heart in order to retain communication with his partner). In all, a 68% chance plus squeeze possibilities. So, are you settling for 12 tricks or are you going for all the marbles?

If the field is weak, you have assured yourself of an excellent score by reaching 6NT, and should therefore settle for 12 tricks. When you know that the field is not likely to reach a contract that you have reached, making the contract should be your first priority. In a stronger field, a better case is made for risking 13 tricks, but it is perfectly reasonable to settle for 12 tricks which will yield a 60-65% score on an average.

As a final note, the caliber of your opposition plays a part in your decision as well. Good players do not underlead an ace against 6NT. If both East and West are good, then chances are that East withheld his ♥A than West underleading it. The next question then is, why did East not play his ♥A? Because he wanted to set a trap for you! If he holds a hand such as

♠Kxxx ♥Axxx ♦J10xx ♣x

Analysis:
A double dummy analysis is not really appropriate here, as knowledge of all four hands renders the play trivial.
Par Contract Analysis:
The par contract on this deal is 7NT by North-South.

Bridge Baron deal No : N3088-53168-10635-04561-88534-09249