There are several situations where it pays dividends to play similar or identical methods for different auctions. However, this is not necessarily best practice, even if it requires less long-term memory.
Two situations that are often discussed at length are responding after interference over a 1N opening (example), and responding after a 1N overcall (example). In particular, should Stayman, Jacoby transfers, or other methods be applied the same way as in the unopposed auction 1N (P) ?
In some cases, "systems on" does not feel like a significant loss and may be applied easily. Some examples include when the opposition doubles or overcalls 2C, or when partner overcalled 1C or 1D with 1N.
However, best practice is to consider how the information given by the opening affects the partnership's possible contracts. It makes little sense to have a bid that "transfers" to a suit mentioned by opener. For example,
(1H) 1N (P) 2D
is nothing short of meaningless if it shows a heart suit.
With this in mind, I recommend the following treatments in the situations outlined at the beginning:
Two situations that are often discussed at length are responding after interference over a 1N opening (example), and responding after a 1N overcall (example). In particular, should Stayman, Jacoby transfers, or other methods be applied the same way as in the unopposed auction 1N (P) ?
In some cases, "systems on" does not feel like a significant loss and may be applied easily. Some examples include when the opposition doubles or overcalls 2C, or when partner overcalled 1C or 1D with 1N.
However, best practice is to consider how the information given by the opening affects the partnership's possible contracts. It makes little sense to have a bid that "transfers" to a suit mentioned by opener. For example,
(1H) 1N (P) 2D
is nothing short of meaningless if it shows a heart suit.
With this in mind, I recommend the following treatments in the situations outlined at the beginning:
- Lebensohl after they overcall a 1N opening
- When the overcall specifies two suits, use an Unusual v Unusual approach in showing the two unbid suits
- When the overcall specifies either one suit or another (e.g. Multi 2D), X sets a force
- After 2C (any one suit), X sets a force
- After (1m) 1N (P) ?
- Normal systems apply, including transfers to minors
- After (1H) 1N (P) ?
- 2C 5 + D or 4S INV+
- 2D 4S < INV
- 2H 5+ S
- 2S 6+ C
- 2N + undefined
- After (1S) 1N (P) ?
- 2C 5+ D or 4H INV
- 2D 5+ H
- 2H 4H p/c
- 2S 6+ C
- 2N + Undefined