Hands are from Soledad Club, September 24, 2018.
South: ♠AKQ1074 ♥Q ♦AQJ2 ♣106
North: ♠86 ♥AK8 ♦K109765 ♣K3
This hand shows the advantage of 2/1 in regard to slam bidding. South opens 1♠ and North bids 2♦ (game forcing in 2/1). South can bid a simple 3♦, knowing it cannot be passed. North will bid 3NT—right-siding the notrump, so that precious the ♣K is protected. This 3NT bid should also promise two spades. So, South can now envision tricks in TWO long suits: South's spades and North's (presumed five or more) diamonds.
South can now bid 4♦—a slam try in diamonds (since you are going past 3NT) or Minorwood, depending on partnership agreement. If N/S play 4♦ as Minorwood, North will bid 4NT, showing two Key Cards without the Queen. South will expect North's Ace to be either in hearts or in clubs, with the King in the other rounded suit (for the NT bid), so will put the contract in 6NT. If 4♦ is a general slam try, North will bid 4♥ (control). South will bid 4♠. North will bid 4NT (temporizing) and South will bid 5♠ which should imply concern only about clubs. [This leaves room for North to sign off at 5NT if her club holding is QJx.] Now North can bid 6NT.
On either sequence, poor East will have to lead a club from ♣Q42—scary—in order to hold N/S to 12 tricks. Otherwise declares has 15 top tricks: six spades, six diamonds, and three hearts.
East: ♠K10 ♥AKQ652 ♦AQJ3 ♣K
West: ♠AJ9 ♥98 ♦K8764 ♣Q53
This hand is a bit of a bidding challenge. Although East has a (theoretically) 3-loser hand, two-suited hands are very difficult to describe if you open 2♣, taking up a whole round of bidding. I would open 1♥, intending to jump shift next. West will bid 1NT in most cases, although some Standard American bidders will venture 2♦. Over 1NT, East will jump 3♦ and West will bid 3NT.
Now East can bid 4♦ (slam try or Minorwood, depending on partnership agreement). If Minorwood, West will bid 4NT (two Key Cards without the Queen). If a generalized slam try, West will bid 4♠, showing a control. East's major decision will be whether to bid the safest contract of 6♦, or make the greedier matchpoint bid of 6♥—expecting partner to have two hearts for her no trump bid. And, East can make the most greedy of all bid of 6NT! On the Minorwood route, East knows that West has either the two black Aces, or one black Ace, the ♦K, and a Queen in the other black suit (again, thanks to the NT bid). On the general slam try route, East knows that West has the ♠A and either the ♣A with no diamond card or the ♣Q and the ♦K. Either way, one black suit is double-stopped, and E/W own the King and Queen in the other black suit, so can lose only one trick there. So 6NT is perfectly reasonable.
If West bid 2♦ over 1♥, East will bid 4♦ (Minorwood) or 4NT (if Minorwood is not available). The final contract will be 6♦ in all probability as East will not be able to find out about the key the ♣Q.
Finally, if East elects to open 2♣ anyway, West will bid 2♦ (waiting) and East will bid 2♥ (suit). This is a rare case where 2NT is the best rebid by the weaker hand (showing about 8-11 HCP) and something in each of the unbid suits. East will probably bid 4♣ (Gerber), but end up unsure WHICH black Ace West has. East will expect the ♦K in the East hand and hopefully a black Queen in the suit in which West does NOT have the Ace. However, East cannot be sure. West could easily have ♣J10xx, for example. So, East is most likely to place the contract in 6♥, protecting her the ♠K on the opening lead—in case partner's Ace is the ♣A. Again, East expects two hearts in the West for the no trump rebid and the ♦K. So East expects to take six heart tricks, four diamond tricks, and the Ace and King in ONE of the black suits. However, in case West has the ♠A, the ♦K and ♣J10xx, cannot risk 6NT.
So, we see a variety of auctions, and the possibility of THREE different slams being bid.