With both sides vulnerable at matchpoints, left hand opponent (LHO) dealt and bid 1 diamond. Two passes followed.
I doubled (takeout) with ♠ KJT5 ♡ AJT4 ♢ Q5 ♣ AT4. LHO rebid 2 clubs. Partner bid 2NT, and three passes followed. Partner was upset with me, because she made 3NT holding ♠ AQ7 ♡ Q86 ♢KT42 ♣ J98.
The reason I passed instead of bidding 3NT was that I had put partner on about 10 high card points for her bid of 2NT. Put another way, I expected her to have hand like the one she had, but with only one, not both of the major suit queens.
With both queens, she would make 3NT, with neither queen, she would go down, with one queen, she may or may not make 3NT. Overall, I estimated that our chances at 50-50.
We got a bottom because everyone else bid (and made) 3NT. That compares with the top we would gotten if everyone else had gone down one.
Was my estimate of 50-50 a reasonable one? Given this assumption, was it reasonable for me to pass 2NT?
Should partner have bid 3NT herself with 12 high card points opposite my presumed 13 (actually had 15)? Or did she reasonably believe that I might be doubling "light" in fourth position?