==== 2nt opening ====
20-22 BAL. may have 5 card major, but we have no way to detect this (NO puppet stayman)
  * 3C/D/H = normal stayman and transfers
  * 4C/D = super texas
  * 3S = :!: special. a hand with one or both minors. opener bid 3NT (or 4C with 44 minor) and then
    * 4C = both minors, longer clubs (at least 5 clubs + 4 diamonds). then, 4D sets diamonds as fit, 4H/S sets clubs as fit (cuebid), 4NT reject
    * 4D = both minors, longer diamonds. then 4H set clubs as fit, 4S sets diamonds as fit, 4NT=reject.
    * 4H = club onesuiter, slam INV (4NT keycard, 5C reject invitation)
    * 4S = diamons onesuiter, slam INV (4NT keycard, 5D reject invitation)