jillybean, on 2012-April-16, 14:47, said:
As phil_20686 touches on, I play 2C/1M as gf clubs or balanced, most often a 3 card M raise and this is not a hand I would have made a gf 'clubs' bid on. How does this agreement affect this appraoch? Partner does not know I have clubs until later, 2♣/1M I could be as few as 2. (yes, we alert)
Often it develops through the auction. If, for example, you show unbalanced, then clubs are natural.
Consider 1♠-P-2♣-P-2♠-P-4♦ as a simple example. If 4♦ is a splinter (caveat for Mike), you cannot have started with a balanced hand. Therefore, the club call must be natural.
If the auction takes longer, like 1♠-2♣, 2♦-2♠, 3♣-4♦(splinter assumed -- for Mike), you might still get the message sent.
There can be auctions where it gets difficult to handle, but then that also is a reason to consider alternatives. Here, none of the majority of rebids from Opener will cause a problem, so 2♣ seems easy. With different structures, or different patterns, the hand might foretell a problem and argue for an alternative like a Splinter or Jac2NT (if OK with Mike).
BTW -- since you now established that 2♠ rebids promise 5+, the same principles apply that I mentioned earlier. Opener still is very likely to respond 2♦ or 2♥. But, I would recommend in this specific auction adding in 2♦ by Opener as "diamonds or balanced," both because a lot of good players are doing this now (apparently) and because it just makes life easier in the long run. But, that's just a proposal.