[sfi]

jogs, on 2016-November-20, 18:22, said:

1♠ weaker than pass. What does that mean?
I think 1♠ should show shape, meaning 4 spades and 5+ hearts. Promises no extras HCP. But also does not deny extra HCP.

It means that it shows a minimum hand with 4+ spades and 5+ hearts. A better hand with the same shape but extras would pass first and then bid spades later if doubling them for penalty does not seem to be appropriate.

I can't speak for this partnership, but I would expect opener to be showing a hand that cannot force to game opposite a minimum redouble.

[msjennifer]

I, personally,cannot imagine anyone bidding 1♠ after the bidding which preceded.It must be a psychic bid.With a 4-5 weak hand anyone will pass or bid 2H but not 1S.In view of the circumstances described 3S has to be a natural bid.His partner is free to pass this bid.With a game forcing hand the bid would have been 2H over 1S and later followed by 3S.

[SteveMoe]

Cyberyeti, on 2016-November-20, 10:16, said:

Do you know this immediately ? or only after the 3♠ bid am I not allowed to double again with a 31(45)/3055/40(45)/4144 big hand

While 3=1=(45) is possible, double of a second suit is penalty oriented (optional or not). Would expect the second double with 3=1=(45) must be on better strength than a mere opening hand. It is not an attempt to get to a minor suit because a pass would communicate that hand. So, yes, penalty.

[GrahamJson]

It's impossible to answer these questions without knowing more about the players. The redouble should show 9 or 10 plus, balanced, but I have seen many players on BBO redouble just to show that they hold a few hearts. The 1S rebid should show a distributional hand, but could be someone having a bit of a joke. The second double and the 3S bid must both show spades, but some players are obsessed with negative doubles and fancy cue bids, usually looking for 3NT. The 3C bid should show values, as with clubs and a poor hand you would bid 2C earlier.

Anyway, if you are west you should trust partber's bidding, not oppo's. Partner must be showing a great suit, but maybe not a long one. Perhaps AKJ10x x AKx QJx.