F or NF - Part 2 of 5

Author: Larry Cohen
Date of publish: 03/28/2016
Level: Intermediate to Advanced

F or NF?

Due to (constant) student request, I have given in and written about this annoyingly tricky topic.

How hard can it be? "Just tell us Larry, which bids are forcing and which are not."

It is very hard. It requires study, memory and sometimes partnership agreement (PA).

F versus GF

In this series, it is important to recognize the difference between Forcing (F) and Game Forcing (GF). "Forcing" (F) means your partner "cannot" pass the bid. If he does pass, he does so at his own peril. I might do it once a decade. Suppose my partner opens and I dredge up a response with a very weak shapely hand. He makes a forcing rebid but I bail out with a pass. I'd better be right! "Game Forcing" (GF) means neither partner can pass below game.


In this 5-part series, I plan to break it down as follows:

  1. Our opening bid, response and opener's rebid (with no interference)
  2. The fourth bid and beyond of our auction (with no interference)
  3. After Overcalls (by us or the opponents)
  4. Auctions with Doubles
  5. Other/Conventions

Last month, we looked at #1) -- Our opening bid, response and opener's rebid.

In this article, we address #2:

 2) The fourth bid and beyond of our auction (with no interference)

Again, we assume no interference and that we are not in a 2/1 GF auction (where obviously we are forced until game is reached). Let's start with auctions where our response is 1-of-a-suit.

Opener Rebids on the 1 level in a new suit:

After 1 of a suit-1 of a suit, what if opener bids a 3rd suit? Let's start where the third bid is still on the 1-level. So, we are looking at these auctions: 1♠-1♠-1♠, 1♠-1♠-1♠ and 1♠-1♠-1♠. In all cases, responder's bid of the 4th suit is forcing. So, in the auctions above, it would be 1♠, 2♠ and 2♠ respectively (though not all partnerships agree on 1♠-1♠-1♠-1♠). For more on fourth-suit forcing, click the link. If responder bids anything but the 4th suit, it is not forcing. His bids of 1NT, 2NT or 3NT can end the auction. If he repeats his suit or raises opener's suit (on any level) it can end the auction.

Opener Rebids on the 2 level in a suit:

What if opener's rebid was a new suit on the two-level? If opener reverses or jumpshifts, that is forcing (other than a jump rebid of 2NT which is 18-19 balanced). Any other new suit bid on the two-level by opener is NF (for example, 1♠-1♠-2♠, 1♠-1♠-2♠, 1♠-1♠-2♠ or 1♠-1♠-2♠). So, what if responder bids over any of these NF rebids? If he repeats his own suit, it is weak, NF. If he jump rebids his suit to the 3-level, it is invitational (NF). If he jump rebids to game, that is also NF. If he raises opener's suit to the 3-level it is NF. If he bids 2NT it is invitational (NF). Jumping to 3NT is obviously NF. Really, the only way for responder to force is to use 4th suit forcing.

What if opener's rebid is 2 of his own suit? If opener rebids his suit on the two-level, that shows a 6-card (almost always) suit and is surely NF. So, we are talking about these starts: , 1♠-1 any-2♠, 1♠-1 any-2♠, 1♠-1 any-2♠ and 1♠-any-2♠. After any of those rebids, responder has to bid a new suit to force. Anything else by responder (notrump, repeating his suit, or raising opener's suit) is NF.

Note: If the auction begins 1 any-1NT-2 of a suit, there isn't really any forcing bid the responder can make. If he bids a new suit, it is NF. If he raises either of opener's suits, it is NF. If he bids notrump, it is NF. The only forcing bid is "the impossible 2♠." What is this?  It starts 1 any-1NT-2-any-2♠. Responder can't have 4 spades (since he didn't bid 1♠), so 2♠ is forcing. Typically it is some maximum with support for opener's second suit.

Opener Rebids on the 3 level in a suit:

What if opener's rebid was on the three-level? Again, opener's jumpshift is F (GF). Opener's jump rebid (1♠-1♠-3♠, for example) is NF. Opener's jump raise (1♠-1♠-3♠, for example) is also NF.  What if responder bids again after one of those NF rebids? Anything responder does is GF! So, for example, 1♠-1♠-3♠-3♠ is forcing.  

Opener Rebids Notrump:

What about if the auction starts 1 of a suit-1 of a suit-1NT? These are the auctions: 1♠-1♠-1NT, 1♠-1MAJ-1NT, 1♠-1MAJ-1NT, 1♠-1♠-1NT. In all cases, opener is showing 12-14 balanced.

Raises of notrump (even 4NT) are natural and not forcing. Repeating a previously bid suit (even jumping) is not forcing. What about bidding a new suit? Now we get into PA. A lot depends on whether or not the partnership uses new-minor forcing. So, 1♠-1♠-1NT-2♠ would not be forcing if new-minor forcing were available. Furthermore, jumps in new suits (1♠-1♠-1NT-3♠ might be played as weak (since with a decent hand, responder would start with new-minor forcing). This complex area is all a matter of PA.

If opener rebids 2NT, new-minor is also a possibility. Unless using a special convention (such as Wolff signoff), any suit bid on the three level by responder should be forcing (for example, 1♠-1♠-2NT-3♠).

Opener's Rebid is none of the above:

If opener jumpshifts, the partnership is forced to game (so anything by responder below game is forcing).

If opener reverses, it is not GF, but is forcing one round. Now, we are back to PA and you can read more about reverses by clicking the link.



I did warn you that this F or NF topic is not easy.

In the next article, we explore auctions with overcalls.


Is the last bid in this auction F or NF (no interference)?

A)  1♠ 1♠  2♠ 2♠
 B)  1♠ 1♠ 1♠ 3♠
C)   1♠ 1♠ 2♠ 3♠
 D)  1♠ 1♠ 1♠ 2♠
E)  1♠ 1♠ 1NT 3♠
F)  1♠ 1NT 2♠ 2♠
G)  1 ♠ 1♠ 1♠ 3♠
H)  1♠ 1♠ 1♠ 2NT
I)  1♠ 1♠ 2♠ 3♠
J)  1♠ 1♠ 2NT 3♠
K)  1♠ 1♠ 1NT 4♠
L)  1♠ 1♠ 3♠ 3♠

Each answer can be explained by carefully looking at the detail above.









A) F
D) F
J) F
L) F