thepossum, on 2020-November-16, 03:52, said:
Note. It has nothing to do with my 2D bid. Most people doubled etc
Well, if most people bid differently to you, then GIB will regularly take a different line, so it's quite possible the difference *was* due to your 2
♦ bid (even if that bid should be completely irrelevant; you know how weird GIB is in this area).
But it's hard to know why other tables were different without seeing what other tables actually did. If "most" tables made exactly the same first two leads against 4
♠, then 91% should be impossible, but the reason should be straightforward if you can show one of those tables that got a different result after that start.
Perhaps against those who doubled, East did play for the squeeze. After ruffing out the hearts, it ran trumps, and South came down to the ace of diamonds and J8 of clubs. East then leads a low club, and South mistakenly plays the jack to 'force out the ace', throwing away the club trick.
But it seems that a significant enough chunk of players would lead a club or diamond at trick 2 as others have mentioned.