[billw55]

Agree, this deal is a textbook advertisement for using lebensohl in such situations. West wants to show his extra strength, but has no easy natural bid to do so.

Using simple methods, 3♦ could be bid with zero points - this makes it hard for east to make a good decision. TylerE's auction is somewhat simple, although N/B players may not recognize the stopper ask. Perhaps simplest of all is for west to bid 2NT (natural) which should show a stopper and modest values. The hand is not ideal for this, but it might be the best you can do with N/B level methods. At least with ♠Axx there is a good chance of isolating south's spades by holding up twice.

Anyway, both east's 4♠ and west's final pass are bad bids.

[fbuijsen]

East's initial double is fine. West's 3♦ bid is OK too; though west has quite maximum values for the bid, but the weakness of the suit warrants some cautiousness.
East's 4♠ is a strange bid. The normal standard meaning for the bid is a control in spades (probably first round control even) and slam-going, establishing diamonds as trumps. Note that east doesn't have the promised control.
West's pass of 4♠ is absurd. West actually has a magnificent hand now, with 2 aces. A jump to 6♦ is the simple bid, but it's reasonable to try for the grand slam here, since east is promising a massive hand (inviting slam opposite a possible zero point hand). Still, seeing all hands it feels like a bit of result oriented argument. Just bid 6♦ at this point.

I would prefer this auction:
2♠ - p - p dbl
p - 3♦ - p - 3♠
p - 3NT - p - 4♣ (now a club cue with diamonds as trumps)
p - 4♥ - p - 5♦
p - 6♦

[PhilKing]

East's 4♠ was probably a misclick.

West got confused and lost their mind.

As to the theory, after a fourth seat double, I play 2NT as natural, showing nominally 8-11 points. The reason is that our most common hand-type on this particular auction is a moderate hand with something in their suit (since there was no raise). So it would go:

P X
2NT 3♣
3♦ 4♦
4♥ 5♣(East could Blackwood, but it's a bad habit with two losers in spades - pards stopper is sometimes JTxx)
5♠ 6♦

This should get you a good result. East can't underwrite seven, since West could be 4252, so there is no parking space for the heart loser.

[helene_t]

4♠ is a very good bid: it means "we can probably make 7♦ if opps think I have a void in spades".

[PhilG007]

The villain in this deal was most definitely East. If you make a bid that partner doesn't understand the
meaning of,it's YOUR FAULT. In a strange or casual partnership,I always try to play as simple a system as
possible. This is especially important if the partner is a beginner/novice.