The slam on Board 3 is better than 35%.
If you play a spade to the ten, suit-play says that your chances for no loser in spades is 13.6% and for one loser 62.8%
Of these 62.8% you will always make when the diamond finesse works. So your chances of success are at least 13.6% + 62.8/2% = 45% .
A spade to the queen is probably slightly better.
However, it does give up on playing spade for no loser and it looses if West has KJ9x in spades and the king of diamonds.
6 Spades makes double dummy 57% of the time.
I do not think that on Board 5 overtaking the heart king is the best play, though it works well on the actual layout.
If you overtake and play a spade to the queen how do you continue?
Cashing the spade ace is dangerous if spades are 3-1, since you devoid yourself of dummy entries to establish your diamonds.
Diamonds could be 4-1 too.
I favor the following line:
Heart king. Ace of diamonds, diamond. Win club return with the ace. Ace of spades. Diamond ruff with the jack.
Somewhat unlucky that this line gives you only 10 tricks, but is fairly safe even if spades are 3-1 and diamonds do not break.
The slam on Board 3 is better than 35%.
If you play a spade to the ten, suit-play says that your chances for no loser in spades is 13.6% and for one loser 62.8%
Of these 62.8% you will always make when the diamond finesse works. So your chances of success are at least 13.6% + 62.8/2% = 45% .
A spade to the queen is probably slightly better.
However, it does give up on playing spade for no loser and it looses if West has KJ9x in spades and the king of diamonds.
6 Spades makes double dummy 57% of the time.
I do not think that on Board 5 overtaking the heart king is the best play, though it works well on the actual layout.
If you overtake and play a spade to the queen how do you continue?
Cashing the spade ace is dangerous if spades are 3-1, since you devoid yourself of dummy entries to establish your diamonds.
Diamonds could be 4-1 too.
I favor the following line:
Heart king. Ace of diamonds, diamond. Win club return with the ace. Ace of spades. Diamond ruff with the jack.
Somewhat unlucky that this line gives you only 10 tricks, but is fairly safe even if spades are 3-1 and diamonds do not break.