Wednesday, January 30, 2008

Unbalanced Diamond Opening

I was intrigued when I saw that Marshall Miles introduced "His System," which included an unbalanced diamond opening. I have used an unbalanced diamond opening for about 20 years, but not exactly what he describes. As the technique does have some "slam aspirational" benefits, and thus is perhaps relevant to this blog's theme, I thought I'd share.

Natural 5-card Major opening structures usually feature some variant as to "how many diamonds" if you open 1D. Maybe better minor, maybe 3 only if 4432, maybe 4+ (open 1♣ if 4432). I have seen 5+ as well.

My preference is 4+ if unbalanced, or 6+ (possibly with an exception if 2245/2254). This means any 4-4-4-1 (with diamonds), or 5 diamonds and 5431/5530/5440/5521, or 6+ diamonds. 1♣, then, will promise either (1) any balanced hand with at least two clubs (could, e.g., be 3352) or (2) any unbalanced hand with at least four clubs (same patterns as for 1D).

The obvious downside is that 1♣ is nebulous, although those who have used a nebulous 1D will know that a nebulous opening has some unexpected benefits (harder to make TOX when short in the other minor, picking off the opp's minor, less info for leads for the opponents, etc.).

The main benefit is that a 1D opening is sort of a min-splinter before the fit is found. A simple example. Your partner opens 1D and you respond 1♠. If the 1D opening was unbalanced, a 2♠ raise from partner will guarantee a stiff or void on the outside. As a stiff and a fit is worth about 3 points, the minimum opening range of maybe 11-14 now will be 14-17 by adding in the known shortness value. This makes game tries easier. BTW -- the relay should usually ask for the stiff, perhaps with a way to show min/max or 3-card/4-card support.

Note, that the ability to show the shape immediately allows Opener to not bid as aggressively. With a 16-17 count, because of the shortness value, you might ordinarily want to jump. As the 16-17 count is close to partner's expectations with an unbalanced diamond opening, however, you simply raise and trust partner to push when it matters. +110 is great also.

The obvious other benefit is in slam exploration. Knowing of the stiff immediately allows Responder to assess slam prospects at a lower level.

Some subtleties. 1D-P-1M-P-1NT is typically stiff in Responder's major and otherwise "balanced." Thus, 1D-P-1♥-P-1NT will almost assuredly be the auction for when Opener has 3154 pattern. This can help in minor slam exploration, and even with exploration of Opener's stiff suit. I mean, 1D-P-1♥-P-1NT-P-3♥ now shows a suit playable opposite a stiff.

There are many other inferential benefits to this approach. If anyone wants to discuss this more, feel free to email me.


Anonymous said...

Very good post. The approach you're describing here is one of my favourites, and I am 90% on your wavelength.

The 10% is that I open 1D holding a 1345 or 3145 too: so, 1D - 1M - 2C shows exactly four diamonds and usually five clubs (occasionally four in 1D - 1S - 2C, from a 1444). As a consequence, I need the 1NT rebid to show five diamonds and a second suit that cannot be bid at a comfortable level: clubs or, over 1S, possibly hearts. A stiff in partner's suit is possible, but not guaranteed.

In a more sophisticated version, 1NT could also include a number of strong hands (like Gazzilli 2C after opening 1M), that can be described over a 2C relay by responder.

Francesco (NickToll)

Kenneth Rexford, Esq. said...

I have used alternative structures here, as well as the canape approach. However, I typically defined strength rather than minor preference. So, for instance, a 1NT rebid might typically show a weak minor two-suiter, whereas a 2♣ call would be stronger.

I found, however, that the major bid by Responder makes a difference. Consider the difference.

1D-P-1♥-P-? Opener would bid 1♠ with four spades. Thus, 1NT intuitively denies four spades, of course. In this sequence, it seems to make sense for 1NT to say one thing about the minors (longer diamonds perhaps, or weaker) and 2♣ to say something different (club canape perhaps, or strong).

However, 1D-P-1♠-P-1NT is a different beast, because Responder has preempted a 1♥ rebid by Opener. In this sequence, it may be better to have 1NT imply/show four hearts, and cover all minor hands through 2♣. Or, alternatively, have 2♣ show hearts and 1NT both minors. Or, "transfers," (2D for weak diamond-heart, 2♥ for true reverse, 2♣ just diamonds, 1NT both minors).

In other words, as the needs of the auction are different, so also should the discussion be different.

That said, I personally rejected the club canape a while ago because I saw little difficulty in handling these hands through a 1♣ opening. Thus, for me the strength distinguishing (more HCP or more shape) after a 1♥ response, and the "hidden hearts" meaning after a 1♠ response, made the most sense.