To have a double squeeze you want both defenders to have 2 of the card you have Ax of, and one each to have one of the cards you have one of. So for the opposite, the defenders want something like this:
Now they have something they can throw with no upset, east keeps his 2 diamonds while west can throw one, so west can keep the club which east can throw. If you choose the other way, just reverse the words "club" and "diamond" for the above. If they choose to do this, reversing the minors in dummy doesn't help, then the diamond is already high, so the club and spade can never be high, and they can BOTH throw diamonds with no ill-effects.
For this to happen, west needs to be able to have BOTH a club, AND a diamond at the end, he throws the one dummy has Ax in, and east makes sure to have 2 in that one. So, the DS CAN'T happen (assuming very good defense) with both minors 4-3. At least one has to be 5-2 so west can only have 1 of them, and the one west has, you keep Ax in!
What if they are both 5-2 with east? You could have a simple squeeze with the minors. You would just run your hearts, keep Axx in both minors, and when east discards a minor leaving him with 2 of them, you throw the other, can play A and K (or just the A if you used the king already) to get rid of both people's holdings, and have the third one for trick #13.
You could find out by seeing how many hearts east has. If two, he might have 5/5 minors, but then he might have 6/4, in which case the DS is on. How do you know?? You can play A and K in a minor to see if west shows out. If he does you're fine, cause you need Ax in the one west HAS and he discarded on the other so its ok. If he doesn't discard you're not fine cause if he started with 4, you need the Ax for the DS.
Maybe you could start with a SS on east and somehow figure out whether he has a 6-4 or a 5-5, and keep the Ax in the 4 cd suit if he has one then do a double squeeze. And if he had 5-5 keep going with the simple one. If he has more than 2 hearts ... try to get a clue about which one east is long in (was the
♣9 meant to tell us?) then cash the AK of it so you have the Ax of the one west has.
Well ... probably what i have said is all wrong, and I don't think I can go any further. It's confusing!!
Beginner's problems should be counting a defender's points and figuring out whether to play the K or J of a suit! Shouldn't be squeezes :-(
Bidding unimportant but included for completeness:
1♦*-1♥*:10-15 unbalanced, no 5cM, (at least 1 A or 2 K); gf relay
2♦*-2♥*:3 suits including ♣+♠;relay
2♠*-2NT*:short hearts;relay
3♣*-3♥*:4144; key card in spades
3NT*-4♣*:3 or 0 key cards; how about the Q
5♠*-7nt:Have the Q, don't have any K; we have them all
opening lead 7♥