[pilowsky]

Recently, I was invited to play in a session where I know that a well-known pair who play a forcing pass system will be present. As an existentialist, this system speaks to me. After all, the pass contains the thing in itself. Non-vulnerable opener may have a hand equivalent to 1NT or 2♣️. What should I do as LHO. A search came up with at least 3 ideas that I list as links at the end of this post. I would be interested in your thoughts. This also bears on the question of people that open with a strong 1♣️ which has similar thinking behind it.
My initial plan was: (remember forcing pass applies only not vul v vul opener has 13+ points any shape).
So loosely based on modified Cappelletti, here are my suggestions. All comment welcome.
OPENER passes
CALL MEANING
PASS I HAVE NOTHING
1♣ DOUBLE ≅ TO AN OPENING HAND
1NT YOUR 1NT BID
2♣️ MAJORS
EVERYTHING ELSE AS USUAL

[Zelandakh]

First of all, the subject of generically defending a FP system makes as much sense as generically defending a system with one or more artificial openings and one or more natural openings. There is a huge family behind the broad categorisation and specifics matter.

There are some generalisations though. As your first link states, defending the FP itself is generally extremely easy. Many defensive schemes involve passing initially with a good hand and bidding on most weak hands with shape. The nature of the defences are generally akin to those of strong club openings or sometimes of mixed (Swedish/Polish) ones.

The most difficult part of the system to defend is usually the fert, so the first question to ask a FP pair is whether their system uses just a single fert and what the fert call or calls are. Occasionally one sees a FP system with a 1m fert but these turn out to be quite easy to defend. More aggressive systems will use higher ferts though and these can genuinely be quite difficult to meet. As an example, your third link is to a system with a single 1♠ fert whereas your second link uses all of 1♣, 1♦, 1♥ and 1♠ as ferts. While it might seem on the surface that having the opps sort out their weak hands like that would make life easier for them, in truth it really just makes life easier for us (the opps) so I would expect the system in link 3 to be the more difficult to defend.

If you genuinely would like some advice on meeting the FP system you will face then I would suggest that you post the full system in as much detail as you know. There are some posters here that have experience in playing both with and against unusual methods and can almost certainly provide a good defensive scheme. I would not like to suggest a generic defence though as the variance between different members of the FP family is too large.

[pilowsky]

Thanks, the 3rd link is the system I expect to face.

[sfi]

Why not just play one of their recommended defences against the unusual bits? They're simple and they work fine.

[Zelandakh]

pilowsky, on 2020-February-01, 21:14, said:

Thanks, the 3rd link is the system I expect to face.

In this case I would suggest you work from your standard defences as much as possible.

Against their FP, play your strong club defence except bid 1♣ rather than X. I disagree with their assertion that 1NT necessarily has to be strong.
Against their transfer 1m openings use your transfer defence. Typically this will either be X as takeout of their suit and the 1M cue as Michaels, or X as showing the suit bid and the 1M cue being a good takeout of the suit (with a delayed X showing a weaker takeout). The former is probably theoretically better but the latter is playable and familiarity helps.
Similarly for their 1NT opening, X as takeout of diamonds and 2♦ majors makes the most sense.
Against their 2♣ opening, play the same defence as their Precision 2♣ opening.
That leaves 1♠. This is the tricky part. There are 2 main schools of thought here. The traditional one is the "Precision-style" defence given in their notes, except that it is more common to play that a 1NT response to the X shows 6-8 and only the 2♦ and up calls are GF. This is probably your best option. The main alternative is not the "Penalty" defence suggested but to play FP over FP, that is for your pass over their pass to be 13+ any. Supposedly this has been found to be superior to the traditional defence in areas where FP is more commonly employed but I would tend to suggest avoiding it as you will need to spend some time working out additional agreements for it to be fully playable.

But I hand the floor over now to the BBFers with more knowledge in this area to make their own suggestions.

[Kungsgeten]

There's a Swedish fert defense named "Antinonsens", notes here: http://www.syskon.nu...inonsens_01.htm I don't know how well Google translate will work.

If I understand the Antinonsens notes correctly, the defense over the 1S fert would be:

Double = Balanced or spades.
1NT = Clubs.
2C = Diamonds.
2D = Hearts.
2H = Three-suited short spades, 12-16.
2S = Three-suited short spades, 17+.

Over the double advancer will assume that the doubler have 13-15 NT. Advancer's 1NT and 2M are weak, while 2C (8-11) and 2D (12+) is used as Two-way Stayman.

Over the transfer overcalls advancer accepts the transfer if it doesn't seem like we make game. Bidding the step above the accept is artificial and forcing for one round.

Over the three-suited 2H and 2S Lebensohl (2NT) is used to sign-off, while direct three-level suit bids are invitational.

Edit: I found an English version of the notes, with more details: http://www.bridgefed...agicdefense.PDF