This page puts six bridge bidding systems side by side: one chart of the opening bids, one chart of the key responses, and the concrete auctions where the systems split. The six are 2/1 Game Force (our reference system), SAYC, Acol, Standard French, Precision and Polish Club.
If you want the general explanation first (what a bidding system is, natural vs artificial methods, and how the families developed), read the bridge bidding system guide and come back here for the details.
The Opening Bids of Six Systems Side by Side
Ranges are the standard versions; every partnership adjusts a few of them. Bold cells are the ones that differ most from 2/1.
| Opening | 2/1 Game Force | SAYC | Acol | Standard French | Precision | Polish Club |
|---|---|---|---|---|---|---|
| 1♣ | 3+ clubs, 12-21 | 3+ clubs, 12-21 | Natural, usually 4+ | Better minor, 3+ | 16+, artificial | 12-14 balanced, or 15-17 with long clubs, or 18+ any |
| 1♦ | 4+ (three only with 4-4-3-2) | 4+ (three only with 4-4-3-2) | Natural, usually 4+ | Better minor, 3+ | 11-15, may be two cards | 4+ diamonds, 12-17 |
| 1♥ / 1♠ | 5+ cards | 5+ cards | 4+ cards | 5+ cards | 5+ cards, 11-15 | 5+ cards, 12-17 |
| 1NT | 15-17 | 15-17 | 12-14 | 15-17 | 13-15 (or 14-16) | 15-17 |
| 2♣ | Strong, artificial | Strong, artificial | Strong, artificial | Strong: 22-23 balanced or 8-9 tricks | 11-15, long clubs | 11-14, long clubs |
| 2♦ | Weak two | Weak two | Weak two (or strong) | Game force | 11-15, short diamonds | Multi: a weak two in a major |
| 2♥ / 2♠ | Weak two | Weak two | Weak two (or strong) | Weak two | Weak two | Weak, two-suited |
| 2NT | 20-21 | 20-21 | 20-22 | 20-21 | 22-24 (many pairs: both minors) | Weak, five-five in the minors |
Read the chart by rows and the families jump out. The natural systems agree on almost everything except Acol's four-card majors and weak 1NT, and the Standard French 2♦. Precision and Polish Club use 2♣ for a limited club hand, because their strong hands start with 1♣.
TipWhen the opponents play a system you do not know, ask about their 1♣, their 1♦ and their 1NT range before the first board. Those three answers tell you most of what you need.
Key Responses Side by Side
The openings are only half the story. Among the natural systems, the biggest differences are in the responses to a major:
| Auction | 2/1 Game Force | SAYC | Acol | Standard French |
|---|---|---|---|---|
| 1♠ - 1NT | Forcing one round, about 6-12 (semi-forcing for some pairs) | 6-10, not forcing | 6-9, not forcing | 6-10, not forcing |
| 1♠ - 2♣ | Game forcing, about 12+ | About 10+, forcing one round | About 9+, forcing one round | About 11+, forcing one round |
| 1♥ - 2♥ | 3+ trumps, about 6-10 | 3+ trumps, about 6-10 | 4+ trumps, 6-9 | 3+ trumps, about 6-10 |
| 1♥ - 3♥ | Limit raise (many pairs: four trumps, with three trumps through 1NT) | Limit raise, 3+ trumps | Limit raise, 4+ trumps | Limit raise, 4 trumps |
| 1♦ - 1♠ - 1NT | Opener has 12-14 | Opener has 12-14 | Opener has 15-17 | Opener has 12-14 |
Over 1♣ or 1♦, a new suit at the two level is forcing in all four systems; many 2/1 pairs play 1♦ - 2♣ as game forcing too.
Where the Systems Split: Three Auctions
1♠ - 2♣. In 2/1 the 2♣ response sets up a game force, so both players can bid slowly afterwards. In SAYC, Acol and Standard French it is forcing for one round only, so a 10 or 11 point hand can bid it, and both players may have to jump later to show extra values. A 2/1 player with 10 or 11 points starts with the forcing 1NT instead.
2/1: game forcing. SAYC, Acol and Standard French: forcing one round.
See what 1♠ - 2♣ means in all five robot systems with the free Bid Meaning tool.
The 1♣ opening. In 2/1, SAYC and Standard French it shows three or more clubs. In Acol it is usually a real four-card suit. In Precision it shows 16 or more with any shape, and in Polish Club it may be a balanced 12-14 with only two clubs. The same call carries four different messages, which is why the opponents ask about your 1♣ before the first board: compare the 1♣ opening in every system.
The balanced 15-17 hand. 2/1, SAYC, Standard French and Polish Club open it 1NT. Acol opens one of a suit and rebids 1NT, and Precision opens 1♣. The deal below shows what that does to one auction.
Notes on Each System
- 2/1 Game Force: the SAYC openings with a game-forcing two-level response and a forcing 1NT. The most common system among North American tournament players.
- SAYC: the ACBL's fixed card for pick-up partnerships. The same openings as 2/1, with responses that force for one round. SAYC vs 2 over 1 shows every change.
- Acol: the British system, with four-card majors and a 12-14 1NT.
- Standard French: the French federation's teaching system, close to SAYC but with a strong 2♣ and a game-forcing 2♦.
- Precision: a strong 1♣ of 16+, every other opening 11-15. The wider family is in strong club systems.
- Polish Club: a three-way 1♣, with natural, limited openings around it.
Strengths and Weaknesses of Each System
| System | Main strength | Main weakness |
|---|---|---|
| 2/1 Game Force | Plenty of room to explore slam once the game force is on | The forcing 1NT makes opener rebid some awkward hands, even a three-card minor |
| SAYC | Simple, and almost everyone knows it | Two-level responses force only one round, so strong auctions get crowded |
| Acol | The weak 1NT comes up often and takes space from the opponents | A weak 1NT can be doubled for a big penalty; raises on four-card majors can land in 4-3 fits |
| Standard French | Natural and well taught, with a separate game-forcing opening | Fewer partners outside French-speaking countries |
| Precision | Limited openings tell partner the strength at once | The 1♦ opening is vague, and a strong 1♣ invites the opponents to jump in |
| Polish Club | Majors and 1♦ are well defined and limited | The three-way 1♣ is easier for the opponents to disrupt |
Sample Deal: 2/1 and Acol Reach the Same Game Differently
North deals. North has 16 HCP and a balanced 3-4-3-3; South has 11 HCP with four hearts.
North has 16 HCP and a balanced 3-4-3-3; South has 11 HCP and four hearts. Both systems reach 4♥, but by different roads.
In 2/1 or SAYC (and also Standard French and Polish Club, which use the same 15-17 range), North opens 1NT. South has game values and a four-card major, so he bids 2♣ Stayman. North shows hearts and South raises to game.
2/1 or SAYC: 1NT (15-17), Stayman, heart game.
In Acol, 16 points is too strong for the 12-14 notrump. North opens 1♥ on a four-card suit, planning to rebid 1NT to show 15-17. South, with four-card support and 11 points, gives a limit raise to 3♥, and North, well above a minimum, bids game.
Acol: four-card 1♥ opening, limit raise, game.
Double dummy, 4♥ makes eleven tricks on this layout, while 3NT makes only nine: the 4-4 fit lets declarer ruff, and that is worth two tricks. Both systems find the fit; Acol simply finds it one round earlier, because a four-card major opening shows the suit at once. The price of that style comes on other deals, when responder raises with three cards and the fit is only seven. The five-card vs four-card majors guide looks at that trade in detail.
You are the dealer and you play Precision.
You play Precision. What do you open with this hand?
Your hand:
Partner opens 1♣. In which of these systems does that opening say nothing about clubs and promise a strong hand?
Practice Any Bidding System Against Robots
Reading a system is one thing; bidding it at speed is another. The BridgeDummy Bidding Room lets you bid random deals with EPBot robots in five systems: 2/1 Game Force, SAYC, Acol, Precision and Polish Club. You pick your side's system and, separately, the opponents' system, so you can practice your own methods or get used to defending against a strong club. Tap a robot's call to see its meaning in that system.
After each auction, your final contract and the alternatives are solved double dummy on layouts that fit the bidding, and you see the average score of each contract next to yours. For a single tricky decision, What Should I Bid takes your hand and the auction so far and suggests the next call in the system you choose, with its meaning.
If you are still deciding which system to learn, the best bridge bidding system guide gives a recommendation by player type.