What is a Jump Shift
A new suit response, eg “1H” “1S” or “1D” “2C” by a player who has not passed is a one-round force. The one-level bid promises little (maybe only 5 or 6 points), the 2-level is a bit more substantive, at least 9 HCP in a 5-card suit (remember rule of 14). Opener will have arranged his opening bid so no such simple new-suit response will prove embarrassing.
A jump shift is a bid by responder after partner has opened, in an uncontested auction, which skips a whole level of bidding. For example “1D” “2H” or “1C” “2S”. The jump shift establishes a game force: both partners must keep describing their hands until a game level contract is reached. An even higher jump, eg “1H” “3S”, is entirely different and we will address this later.
How and When to Use
Once in a while responder will hold a nice hand after partner has opened—a good suit and opening strength. Some partners will view this as sufficient to jump-shift; after all, opening points opposite opening points should be enough for game. While that may be true, jumping a whole round of bidding can make it harder to decide in what strain to play: your suit, my suit, some yet to be named suit, NT? So to deploy a Jump Shift requires three things: a good suit (and it has to have at least the K and probably the Ace), opening points and a clear idea of the expected strain. The last consideration means you must either have support for your partner which you plan to show at the next opportunity or a suit so good you plan to play it no matter how poor partner’s support. Feel free to jump-shift if you have both! But take it slower if you can’t yet be sure.
Once there has been a jump shift, both players must keep bidding until game is reached. Neither should jump just to show extra values though I suppose you might to show a sub-minimum opening. For example, suppose you opened “1C” intending to rebid 1NT showing 15-17 HCP or 2NT showing 17+HCP or even 3NT showing 19+ HCP. Partner surprises you with a “2H” response and you have no great liking for H, bid NT at the cheapest level “2NT” to show the balanced hand don’t worry that your range is now wider. You will reach game for sure, slam maybe, but you have no idea where yet. As opener, except for not-jumping when you had planned to, bid exactly as you originally planned. Likewise as responder, don’t jump again just to show a long strong suit, a simple rebid will do that. As soon as both partners have named the same suit, it is agreed as trumps. Responder can also indicate a unilateral decision by rebidding his. After genuine or unilateral agreement, new suits are Cue bids showing first round control. RKCB (Roman Keycard Blackwood) asks for key cards including the K of the agreed suit. Recall that the RKCB responses are 5C shows 3 or 0 key cards, 5D shows 4 or 1, 5H shows 2 and denies the Q of trumps, 5S shows 2 key cards and the Q of trumps. This is summarised in the “Slam Conventions” section of the Orpington EBU card found in its own page under training. We briefly discussed subsequent actions after the RKCB response: any level of the agreed suit is a sign off; the next suit up from the RKCB response (unless it is the agreed suit) is a further enquiry.
So to today’s hand.
S: A Q 8
H: J 3
D: A Q 9 3
C: K J 7 6
and not unreasonably opens “1C” intending to bid NT if partner bids “1H”—mostly to show the point range and shape but fortunately also showing complementary stops—or reverse to “2D” over “1S” still showing the strength but now suggesting ruffing values.
But South holds
S: T 4
H: A K Q T 5 4 2
D: 6 4 2
and bids “2H” to show a sound opening bid and, in this case, a self-supporting suit. Now “2NT” from North is perfect showing a balanced hand, something everywhere and tenaces to protect. It must show tolerance for Hearts or North would have bid another suit to show shapeliness. South sets the suit with his second bid “3H”. Now the trump Jack is huge, so N co-operates cheaply with a cue-bid of “3S” showing the A. South is minimum and shows it with “4H” but N has at least and Ace in hand and uses RKCB continuing to ‘6H” over the “5C” response which shows 3 key cards. (A 5S response would just possibly have been embarrassing with perhaps a couple of C losers but the opponents have to find the lead and S has to have something beyond the three top hearts.) So there we are in 6H
W leads a passive trump (luckily as the hand would lose its point if forced to a first round finesse) and S makes a plan. There is nothing to ruff all 7 trumps in the S hand will score anyway as will the AC. Ace of Spades, Ace of diamonds and K of clubs in dummy makes 11 altogether whence comes the twelfth? A successful finesse in D or S would give the twelfth and even if one fails there is time and entries to try the other, together a 75% chance. When you’ve found a good plan, look for a better at least in training, it might seem too time-consuming at table but a few extra seconds won’t harm.
An end play makes the contract certain, even if both finesses fail. Draw trumps and cash the A of Clubs. Now lead a D and cover what W plays. If your card holds this trick, the finesse worked and you have your twelfth. If it fails E is on play—with no hearts. And his lead in any other suit is into a tenace with N playing 4th: 100%! You could say the bidding was a bit overenthusiastic but you should be in slams with a 75% chance of making and if you add end-plays to your capabilities you should find the slams you do bid easier to make.