[PhilG007]

When your partner doubles the opponent's contract for penalties,when should you remove it and when should you leave it in?
This is tricky ground so any advice would not only help me but also the novices and intermediates who read these forums.
I await any replies with interest.

[Stephen Tu]

You bid on generally only when you know something that your partner doesn't, that makes bidding on for your side likely more profitable. This is usually previously undisclosed massive trump fit and/or double fit, that simultaneously makes it more likely you make more (e.g. 5 over 5 game, slam), and less likely that you set the opps enough to compensate or at all (since your huge fit decreases the number of tricks you rate to cash in those suits).

So lots of offensive enhancing shape that you haven't shown in the previous bidding.


Also be aware that many fewer doubles are defined pure penalty anymore compared to 40+ years ago, these days a lot more doubles are defined as "I have too much to pass, but unclear what to do, partner take your best guess". Particularly doubles that are made before your side has established a trump fit somewhere.

[Cyberyeti]

Stephen more or less nails it.

Example, you play constructive weak 2s 6-10, you hold -, QJ109xx, x, QJ109xx you decide to open 2♥ first in green against red (not my choice, but some do), and it goes 4♠-X. Now it's possible but unlikely given the vul that partner has a massive trump stack, but much more likely he has say QJx, A, KJxxx, AKxx where you're not getting rich out of 4♠ and 5♣ could easily make an overtrick.

[johnu]

If partner takes out a large knife, sticks it into the table, doubles, and glares at you to warn against bidding, then you should probably pass. If partner takes out a coin, and flips it a couple of times, and then doubles, they aren't sure and you should takeout the double if you are also unsure.

That being said, some doubles are 100% penalty and you should pass without even looking at your hand. You would have give a specific auction to determine what type of double was made.

[steve2005]

Funny Story. This isn't pulling a penalty double but pulling a sacrifice.
Playing at a club that is a bit away so very rarely visit. RHO has over 10,000 mp and represented our country. LHO has a lot of MP too but dont recall how many.
Cant remember vulnerability but think we were red and opps white.
Bidding goes 3C from partner in 1st seat I bid 3NT
it goes pass pas to RHO who bids 4♦
Which I double ending the auction.
Opps were down 4 as RHO only had 5 diamonds.
As soon as auction RHO asked why LHO didn't pull to their 5-card spade suit saying I obviously had diamonds under control for my double.
What ridiculousness if RHO has 6 diamonds they just had a top board.
And surely I am doubling pretty close to whatever my diamond holding is.

[HardVector]

Stephen pretty much covered it. All I have to add, is that when I hold a void in their suit, I tend to pull penalties if there is a question. Voids are usually offensive and are poor holdings on defense, particularly if you are going to be on lead. When your partner makes a penalty double, normally the correct opening lead is a trump as you are looking to eliminate the ruffing potential, which is going to be the only way they are going to make or get close to their bid. If you have a void, you can't lead a trump which compromises your defense.