We make some adjustments. We open all balanced 11-counts so bump 1NT to 14-16, a useful and common range.
Thus 1D is Precision style, say 11-15 natural or 11-13 balanced. We could also use a Precision 2D opening of “4415 lose one card” but our usual 2D opening is natural, don’t want to lose that.
In fact it’s better in 3rd seat since the lack of a relay means responder’s heart hands are not messed up. Also, 5-4 minors can happily open 1D then rebid 2C or 1NT. So a 3rd hand 2D will nearly always be a 6-carder. Could be shaded, like a strong weak two.
2C in 3rd seat can be similar, optionally with 4-5 minors based on texture. The issue is a 4-card major – the hand that old Precision would open 2C or 2D.
We COULD have 1D as 1+ (even 0+) and be done with it but note that Precisionistas who do that do so because 1M shows 5+ and 2C shows 6+. They might open a punchy 4-card major in 3rd seat but 1+ still applies for them.
Let’s list some of the awkward hands, the club raptors and 3-suiters
a) QTxx AKx x KJxxx
b) QTxx Kxxx xx AKx
c) QTxx, x, AKx KJxxx
a) 2C is possible because 2D still asks for a major. This is an old Precision 2D opener. Really it has to be 1S, hating it. Maybe better to allow 1D on this.
b) 1D as 11-13 balanced is fine. The issue here is that 1D becomes artificial and alertable. That means no 4-card raises and an ambiguous “Alert”.
c) 1D is easy here, but 1D – 1H – 1S is uncharted territory.
