I am South. The bidding goes pass, 1c,1s,3d X. East then bids 4 clubs. I doubled. West made a weak jump shift. That implies that they can not play anything but diamonds. Yes, you have six clubs in the east; but running only increases the level of play. Sometimes you get doubled and go down. Unless you have a clue that the other suit is the place to play , pass and go down two  in three diamonds doubled instead of down three in four clubs doubled. PASS. You can’t run far enough with this bidding sequence!

I am South. Bidding goes: Pass, 1 club, 1 spade, Three diamonds, x, four clubs x. When is a double penalty? How high do you play a negative or responsive double? 

Let’s look at the bidding. North passes ( less than opening values), East can open with one club. I bid 1 spade. Now West makes a weak jump shift. My partner can deduce from this bidding that I likely have opening values. My partner has King doubleton of my suit and a stiff club along with five diamonds to the KQJ. Safe double. When east tries to run, I can easily double their suit. I now know my partner has values and tricks in diamonds. I have a stiff diamond and can ruff diamonds. I have five clubs behind the opener to the Ace 10. 

You are north and dealer. You open the bidding 1 club. LHO doubles. Your partner bids 1 spade. RHO bids two hearts. What do you bid?

This is your hand.

Xx, Kxx, Kxxx, KQJ10.  You have a flat 12 points. You do not have support for your partner's spades. My partner bid two no trump with this hand. Why is that wrong? How many points do I have? How does my partner know? 

Ahhhhh, I did not redouble. A redouble tells your partner you have 10+ points. Now my partner knows that I am capped at nine points. With a weak stopper in hearts, she went down three in two no trump with my six point hand. 

Pass. Pass. Pass. Stay out of trouble! Leave the next decision to me. 

Should you double or should you bid? You are holding this hand and your LHO opens one club. What should you do?

QJxx, AKxxx, AKxx, void clubs. My partner bid 1 heart. Why is this wrong? A simple overcall has a ceiling or a maximum point count. My partner has 17 HCP with a void in clubs. A bid of one heart limits the hand to 15 HCP. Double first. Your hand is too big to simply overcall. If you double and come back in and bid , your partner will know that you have at least 16 HCP. Learning how to correctly use the takeout double is essential to a good bridge game. 

Another example that recently came up. I am south . My RHO opens one heart. I double. LHO passes. My partner bids 2 clubs. RHO bids two hearts and I now bid two no trump. 

My partner is holding:  Jxx, J9, Q1098. QJxx . What should they bid over my two notrump? What do I have in this bidding sequence?  A direct no trump overcall over 1 heart opener is 15-18. I doubled and then came back in and bid two no trump over openers two heart rebid. I have 19-21 points. Basically the equivalent of a two no trump opener. So what should my partner bid? Three no trump. 

I am South. LHO opens bidding 1c. My partner passes at the first opportunity. RHO bids 1 spade. I pass. LHO bids two clubs. . My partner makes a takeout double at the second opportunity. RHO passes. I bid two hearts and LHO bids three clubs . Opponents are vulnerable. I have 10 points. My partner should have ten points. I have AJ10x of opponents clubs and AJxx of hearts. I make a penalty double thinking opponents are too high. They then proceed to make the contract.

This is my partner’s hand:

Xxx, Kxxx, Kxxx, xx. My partner does have the other two suits, but only six points. You can not make a takeout double with this hand. You are leading your partner astray. My partner said that they needed to show me the other two suits. I explained the double also implies points. Understanding how to utilize the takeout double is essential.