hrothgar, on 2011-January-12, 09:15, said:
Hi Adam
There are some additional considerations that need to be factored in to the equation.
Assume for the moment, that a 5 card major player opens 1♠ and the auction starts
1♠ - (P) - 2♠
Assuming that the 5 card major player is using a normal response structure, the opponents know with certainty that the 5 card major opener is resting in an eight+ card fit. In turn, the opponents are relatively well positioned to apply the Law of Total Tricks and make a decision whether to balance or pre-balance.
Now, assume that a MOSCITO player opens 1♥ (showing 4+ spades) and the auction starts
1♥ - (P) - 2♠
In this case, the only thing that the opponents know with certainty is that the 2♠ bidder normally holds exactly three card support. Its unclear whether the opponents are sitting in an eight+ card fit (in which case balancing is pretty important) or a 7 card fit, in which case balancing can easily lead to a poor score. (The way things work out, the MOSCITO partnership will be resting in an 8+ card fit about 52% of the time and a 7 card fit ~48% of the time).
Moreover, the player who opened 1♥ knows
1. His own trump length
2. Partner's trump length (The 2♠ raise promises three card support)
He's in a very good position to make a well informed decision.
I've never been comfortable with that style, whereby a single raise of a likely 4-card major denies 4 trumps. In the early days of Moscito, this was making a necessity of convention.
In 1985, 1
♠ showed 4+
♠s and denied 4
♥s. In response, 1NT was 11+ relay.
Thus a responding hand like
♠Jxx
♥Qx
♦Axxx
♣Qxxx
raised to 2
♠ quite happily, since 1NT was out and he knew the opponents had 8+
♥s. In those days 1
♥ & 1
♠ were 4-card suits 53% of the time. That example was clear enough but Paul Marston also did it on less suitable hands, reaping a benefit when the opponents stepped in, and also when they were afraid to ...
However, auto 3-card raises rate to lose long term in a 2-handed game and opponents are starting to judge these auctions better.
Whatever the reason, Marston started to move some of the 4-carders out of 1M. These days, 11-12 flat opens 1NT, 4-6 hands with long minor show the minor first & there is no denied major. (4-5 hands show long hearts, 5-4 hands show long spades)
With these changes, the chance of 1
♥ (=
♠s) being a 4-carder are around 40%.
That makes a 3-card raise more attractive. Certainly taking out 11-12 flat avoids some silly -300s. However, it still feels wrong at times to routinely bid beyond the TNT. 4333s with 4 trumps should pretend they have 3. I also tend to stay low on hands with 4+ in the other major. So
♠Qxx
♥KTxx
♦Qx
♣JTxx
feels like a 1NT response to 1
♥ (=
♠s) (Or in our case, 1
♦ =
♠s, not
♥s)
Of course you don't want to stretch this too far. If a raise shows 3 or 4, neither will be able to diagnose a 9-card fit and push to the 3-level. I like a bit of flexibility. For us, a jump major raise shows a shapely raise to 2M. That's any hand with 5 trumps, or 4 chunky ones, or 4 and a bit of shape. (That might simply mean a doubleton in opener's denied major. Yes, we still play that way)
It's true that Standard & Precision have an advantage whenever they have a 5-3 major fit but the gain is small. With methods that open 4-card majors, the gain is in finding the 4-4 fit faster, hitting the 3-level quickly with the 4-5 fit, plus messing with the opponents' TNT assumptions.