Loser on a Loser 
            Transfer the Ruff
            Up and Down the Ladder Bids
In a suit contract the Declarer counts losers and then applies one or more of the following strategies: DUMP / TRUMP / or FINESSE. DUMP means to throw (or pitch) a Loser on a Winner.
      A corollary to this strategy is to throw a Loser on a Loser. By throwing away a loser  from one suit on a loser from another suit  Declarer has eliminated a loser. Two losers were lost on only one trick. Tricky, tricky. A special type of Loser on a Loser maneuver is Transferring the Ruff
       Declarer does not want to ruff a particular suit (let's call it SUIT A), but is happy to ruff another suit (let's call it SUIT B). So play suit A, and instead of ruffing SUIT A, DUMP a loser from SUIT B. Now SUIT B can be ruffed. The ruff was transferred from SUIT A to SUIT B. 
       Now let's look at the Example below. In this Example, SUIT A is Spades and SUIT B is Hearts. 
S -----
H 2
C J 9

S 4
H 3

In this Example, Clubs are trump. It is now Declarer's turn to play from the hand. The Declarer does not want to give up the lead by playing Hearts. Instead the losing 4 S is played. Now instead of ruffing the 4 S the 
H is DUMPED on it. Loser on Loser. And now, instead of giving up the lead in Hearts,  the 3 H can be ruffed in Dummy. Thus Transferring the Ruff.

South opens the bidding in one of the minors. Some partnerships would have South open 1 C, then for the rebid make a reverse by bidding Diamonds. Or start with 1 D, then jump in Clubs. South's hand is better than the Minimum (13 - 15 points) and this should be told to partner before making a non-forcing or sign-off bid.
      North must respond with 6+ points and does so by bidding 1 H. Bidding is a common language that is spoken by both members of the partnership. Proper communication is the key to good bidding. 
      The partnership is looking for a fit in the majors. A Bridge hand is like baseball; it is better to play in the majors. The salaries are greater. 
       North with two 4 card majors bids up the ladder, that is Hearts first. (If North had two 5 card majors, the  bid would be down the ladder or Spades first.) Over North's 1 H bid, South's rebids 1S, again looking for that major suit fit. A find! North with 4 Spades supports partner by bidding 2 S. South with a monster hand goes to game in 4 S

The Opening Lead can make or break a contract. So, it is important to get off to a good start. The K D has a lot to offer. Being top of a sequence makes it fairly safe. If Declarer has the A D, then it will be knocked out and the Q D and even J D can be promoted to winners. There is also the possibility of  ruffing the third round of Diamonds. This is a consideration even when holding the Q S. For the Q S is not necessarily a winner. (The K S and J S can be in Dummy and the Q S would be very finessable.) So promoting a high card to a winner; safety; and a possible third round ruff make the K D the best opening lead. 

Dummy comes down. Declarer is thinking and counting. East should be doing the same. Where are the 4 tricks needed to set the contract coming from?
     One Heart trick for sure and possibly a Diamond or two. Maybe partner has a high trump or high Club? 

Dummy comes down with four Spades to the King. Don't panic. A good Bridge player knows when to panic, and the first trick is never the time to do so. Instead count and look confident. 1 Spade loser; 1 Heart loser; 2 Diamond losers; and 1 Club loser. 5 losers. Now panic. No, just kidding. Instead of panicking, find a way of getting rid of 2 losers safely. 
      A trump loser and a Heart loser are unavoidable. A losing Diamond in Dummy can be DUMPED on the Q C after the  A C and K C are played. This would eliminate one of the Diamond losers. But there are still 2 losers to deal with: the 5 C and the third Diamond.  The 5 C be ruffed in Dummy, but the problem is that East can overruff, and the Defense would still make a high trump and a Diamond trick for down one. What to do?
       SOLUTION: trump 2 Diamonds in Dummy by initiating a Loser on a Loser play that would Transfer the Ruff. That is instead of ruffing the fourth Club (5 C), DUMP a losing Diamond on it. (Loser on a Loser.) Then Dummy would be void of Diamonds and the two losing Diamonds in the closed hand can be ruffed in Dummy. (Transferring the Ruff.) 
        PLAN: try to ruff Diamonds in Dummy and later pull 2 rounds of trump. This can be done by DUMPING Diamonds on the Clubs. And instead of trying to ruff the 5 C, (which will lose anyway if ruffed because East will overruff), DUMP a losing Diamond from Dummy. A Loser on a Loser play: throw a losing Diamond away on the losing Club. West will win the 5 C with the J C.
      In other words instead of trying to ruff the losing Club, a losing Diamond will be pitched, which would enable Diamonds to be ruffed. Thus Transferring the Ruff. In this case from Clubs to Diamonds. 
      What about pulling trump? Two trump are needed in Dummy to ruff the two losing Diamonds. Trump must be played after West wins the trick with the J C
      PLAY: Win the first trick with the A D and play 3 rounds of Clubs: A C, K C, and on the Q C DUMP a Diamond. This leaves 1 Diamond left in Dummy. Now for the Loser on Loser and Ruff Transfer: Play the 5 C and pitch Dummy's last Diamond. West wins this with the J C and is on lead. Whatever West returns Declarer will eventually get the lead. Play the K S and A S and then ruff a Diamond. Eventually ruff a Heart in the closed hand and ruff the last Diamond in Dummy. West could come in with his high Spade at anytime. That is all the Defense will get: a high trump; the A H; and the J C. Declarer makes 4 S

1. What happens if Declarer pulls two rounds of trumps before playing the 5 C?

2. Can the hand be made by playing the K S then the A S and then ruffing the 5 C in Dummy?