When partner opens the bidding with a Major suit and right hand opponent makes a takeout double, the modern approach for many expert partnerships is to play transfer bids by Responder.

• If we buy the contract, it is likely to be in the long suit of the weak hand. In this case, the opening bidder will become the declarer - allowing the strong hand to be hidden from the opponents and forcing the strong opponent (the takeout doubler) to be on opening lead.
• Two ways to raise Opener’s suit. The direct raise of partner’s suit is weak and is a blocking raise, while transferring in to partner’s suit is a constructive raise.
• We do lose one call when we play these transfer bids by Responder: the natural 1NT response. This is not much to give up, because in these competitive auctions Responder rarely buys the contract for 1NT, as Advancer will likely bid some 4-card suit at the 2-level with some values. It is also the case that if Opener has a strong hand and we are headed towards game, we do not want Responder to become the declarer in 3NT - we much prefer for the strong hand to declare and for the strong opponent to be on opening lead.

1❤️ - Double - ?

• 1NT Transfer to ♣️, usually 6-card ♣️ suit, 5-9 HCP
• 2♣️ Transfer to ♦️, usually 6-card ♦️ suit, 5-9 HCP
• 2♦️ Constructive ❤️ raise, 7-9 points, 3-4 card ❤️
• 2❤️ Weak raise to 2❤️, 3-7 points, 3-4 card ❤️

1♠️ - Double - ?

• 1NT Transfer to ♣️, usually 6-card ♣️ suit, 5-9 HCP
• 2♣️ Transfer to ♦️, usually 6-card ♦️ suit, 5-9 HCP
• 2♦️ Transfer to ❤️, usually 6-card ❤️ suit, 5-9 HCP
• 2❤️ Constructive ♠️ raise, 7-9 points, 3-4 card ♠️
• 2♠️ Weak raise to 2♠️, 3-7 points, 3-4 card ♠️

1❤️ - Double - 1♠️

• 6+ points, 4-card ♠️

1❤️ - Double - Redouble
1♠️ - Double - Redouble

• Redouble still shows 10+ points. Could have 3-card support.

1❤️ - Double - 2NT
1♠️ - Double - 2NT

• Jordan. 4 cards fit and 10+ HCP

Reference: This Week in Bridge