Quite different from my last post about risky bidding, this time it's a serious underbid, resulting in a missed vul game, and a serious loss of IMP to the opps too
I was East, and opened 2NT on this 21HCP hand, thinking that 2NT opening refers to 20-21 HCP, balanced hand.
Partner passes with a 10HCP hand...
Are there any other alternative interpretations of a 2NT opener that are commonly used which may account for the pass by west? Becoz this is just a random partner from a casual MBC game...
Or should I not have opened 2NT after all?
Plz tell me ur opinion or the correct bidding sequence
Thx

Help

Bidding
W N E S
- - - P
P P 2NT P
P P
Opening lead: ♦2
Result: 2NT+3
+8.00 IMP to NS