When you play bridge in Poland, you may frequently face a pair that use Pilsih Club (no surprise). The notes here might be helpful to understand this ?system designed in hell:
Summary of openings:
1? = 1) 12-14, balanced (no major 5) or
2) 16+ long clubs (5+) or
3) strong (usually 18+), any distribution
1?=12 ? 17, usually 5 diamonds; 4 diamonds only when unless 4441, or 4 diamonds, 5 clubs
1? / 1? = 12 -17, 5 cards
1NT = 15 ? 17
2? = Precision (12-15; 6 clubs or 5 clubs and a major four)
2? = wk two in a major
2 ?/ 2 ? = two-suiter (5 5) hands with hearts / spades, sub-opening strength
2NT = both minors (5 5), sub-opening strength
Polish Club is easy to learn, especially for new players. It is mostly natural and resembles Standard American or French better minor in most auctions.
These are the main features of Polish Club:
1) You don?t open 1 of your best suit when you are afraid of partner passing prematurely. Instead, you open a forcing 1?. These are the hands for the 1? opening:
? AKJ32 ?K2 ?AJ102 ?A3 – 20 HCP
?AK105432 A32 ?KJ3 ?– lots of winning trick based on one long suit
?32 ?AKQ432 ?AQJ2 ?2 – lots of winning tricks based on two-suiter shape.
Partner cannot pass 1? opening. If he is broke, he responds with a negative 1?.
2) You don?t have to make a preference between two unbiddable minor suits in the opening seat. You open 1? when you have a five-card suit (in some cases 4 cards would do); otherwise you open 1? (promises two or more clubs unless strong). Logical: responder cannot raise clubs anyhow (unless he has five of his own), opener might be strong with no clubs whatsoever!
3) Two-level opening are specific: 2? is Precision (unbalanced hand on long clubs, 12-15), 2? is weak Multi (weak two in a major), 2? and 2? show sub-opening two-suiter hands with hearts/spades respectively. 2NT openings shows a sub-opening hand with both minors (strong 2NT opening is included in strong club).
No particular defense is needed against Polish Club. The most popular treatment is natural 2? overcall, and Michaels 2? as showing both majors.