Drury
Modern fashion is if we open 1M in 3rd or 4th seat that Responder uses
2♣ALERT to show a limit raise of that major, so that Opener can sign off
a level lower - in 2M - giving them the ability to open light.
While playing Drury, P-1M-2♦ is natural - 5 diamonds and almost an opening
strength. Meanwhile, P-1NT-2♣-2♦ is also natural - this time probably
showing a weaker hand with diamonds.
And if Responder has clubs? Well, there's no way without going to the
3-level, which should probably be a fit showing jump anyway. However!
if we use 2♦ to show Drury, then now we can show both minors. Specifically:
- P-1M-1NT-P: we are probably okay!
- P-1M-1NT-2♣-2♦: diamonds!
- P-1M-1NT-2♦-(P or 3♦): diamonds!
- P-1♠-1NT-2♥: this is the sad case
- P-1M-1NT-2M: we expect to have adequate play in M
- P-1M-2♣: clubs!