Dealer South, Matchpoint, none vuln.
Bidding was a straightforward 1S:2S:4S, opps silent.
Lead was K of H, followed by HQ, ruffed.
After 2 rounds of trumps I ruffed another heart in hand and established the clubs.
On the 4th round of clubs both opps discarded hearts and on the 5th LHO discarded a diamond and RHO the H Ace.
T this point I Knew that:
1) west had started with 4 diamonds, exactly xx-KQJx-????-xxx
2) east had started with exactley 3D, exactly: xx-Axxxx-???-Qxx
I had to play the diamond suit for the overtrick, holding T9 opposite KJxx in dummy.
I had to find the A or the Q of diamonds.
I knew opponents: west is an international player, who would have doubled, only holding BOTH the diamond Ace AND the DQ (in which case it does not matter what I play);
East is a local expert, who would never think of bidding anything over 2 spades, unless he held both AQ of D (in which case, it does not matter what I play).
So the only info from the bidding i that probably honors are split.
The only small extra info is the length in diamond: West is longer than East.
this means that West has 4 probabilities out of 7 of hlding a specific keycard, and East has 3 probabilities out of 7 of holding the same keycard.
If I apply this reasoning to the Ace, then the result is that West is more likely to hold the Ace and I sholuld play low to the K.
If the Ace is in the right hand and I play to the K, I do not need to know where the Q is.
However, I might also make the same reasoning for the Q: the Q is also a keycard, and as a result, if I neglect the position of the Ace, it is also more likely to be in West.
If the Queen is in the right hand and I play to the J, I do not need to know where the A is.
In short, is it a TOTAL GUESS ?
PS- I played low to the King assuming West's extra length made it slightly more likely he held the Ace.... :-(

Help

Contract is 4S with opps silent