(from System "NIGHTMARE" by Buratti & Lanzarotti)
2♥ OPENING
2♥ -- 2♠ relay (see below)
2NT relay, both minors F1, or 5+♠ GF ==> opener 3♣/3♦ = better minor
==> opener 3♥ = 2-2 minors
==> opener 3♠ = 6♥ + 4♠ (2/1) max
==> opener 3NT = solid suit
3♣/3♦ nat F1
3♥ preempt
3♠ values with ♥ fit
3NT/4♣/4♦ splinter, limit or better, ♠/♣/♦ ==> opener 4♣/4♦ = 4(♣/♦)-2♠ (now 4NT is S/O)
Note: 3NT directly is not to play but ♠ splinter (3NT to play after 2♠ relay)
4♥ to play
2♥ -- 2♠ relay
2NT == 6♥ + 4X --> 3♣ = relay --> opener 3♦/3♥/3♠ = 4♣/4♦/4♠
3♣ == sing minor --> 3♦ = bid game if ♦ singl
3♥ = pass if ♦ singl
3♦ == sing ♠
3♥ == min bal (6.3.2.2)
3♠ == max bal, solid suit
2♠ OPENING
2♠ --> 2NT = relay
3♣ == 6♠-4X 3♦ = relay --> 3♥ = 4♣, 3♠ = 4♦, 3NT = 4♥
3♦ == sing min 3♥ = bid game if ♦ or 3♠ if ♣
3♠ = pass if ♦
3♥ == sing ♥
3♠ == min bal (6.3.2.2)
3NT == max bal, solid suit
Over Interference of 2♥ or 2♠ opener
Over an enemy double,
XX = top honor, or head-hunting
raise = preempt
new suit = shows values
2NT = asks for description
Over an enemy bid,
X = penalty
raise = competitive
new suit = nat, F
lebensohl after x --> 2NT weak or limited -->> https://www.bridgebum.com/lebensohl_over_weak_two.php