Two Over One Game Force, or 2/1 for short, is a bidding style that has improved the Standard (American) system. It’s based on Standard and is a five-card major approach. However, when opener has started with 1♦ or 1♥ or 1♠, and responder, in order to show their own (lower-ranked) suit, bids at the two level, they promise enough strength to force to at least game. Here are all the auctions where 2/1 applies:
- 1♦ p 2♣. Game-forcing. Natural, showing at least four clubs, and at least opening strength (10 points are not enough).
- 1♥ p 2♣/2♦ Game-forcing. Natural, showing at least four clubs or diamonds, and at least opening strength.
- 1♠ p 2♣/2♦/2♥ Game-forcing. Natural, showing at least four clubs or diamonds, or five hearts, and opening+ strength.
2/1 doesn’t happen over 1♣ openings, because it’s always possible to respond at the one-level. If partner opened 1♥ and you held ♠K10642 ♥A10 ♦AQ65 ♣108, you would simply respond 1♠ showing four+ spades and 6+ points. You have made an unlimited and forcing bid. There was no reason to go to the two-level by bidding 2♠. Nor does 2/1 affect your major suit raises such as Bergen, Jacoby 2NT, Splinters. Constructive and obstructive raises apply as normal.
More descriptive auctions: The 2/1 style is more effective and easier than Standard because it’s good to know when you’re in a game forcing auction.
ʽSystem off’ in competition: What happens if the opponents bid, e.g., 1♥- 2♣ (overcall) - 2♦? Now 2♦ is a one round force only - it simply shows a good five+ card suit and 10+ HCP.
Opener’s Rebids: After a 2/1 sequence such as 1♠- p - 2♣, opener shows shape rather than strength. The bidding won’t stop below game and strength can be shown later. The same applies to responder.
How Does 2/1 Help to Locate Slams? Having slower auctions gives both opener and responder more room to agree a suit and to try for slam via cue bidding and then Blackwood.