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This hand was my Board 6 from Day 1 of the March 2019 NABC tournament.
At one table, the play began:
♠4 ♠J ♠Q ♠2
♠K ♠3 ♣2 ♠5
♠A ♠7 ♣6 ♠6
♣4
At another table, the play began:
♠4 ♠9 ♠Q ♠2
♠K ♠3 ♣2 ♠5
♠A ♠7 ♥7 ♠6
♥K
The only difference between the players was whether the ♠J or ♠9 was played from dummy's J109 sequence.
Now, I might expect GIB to analyze differently depending on equivalent cards from a closed hand (provided that both of the other hands could have cards remaining), but it seems to me that GIB should analyze the same for any choice of the three visible equivalent cards played from dummy. I don't wish to speculate which choice GIB should make (though in this case, ♥K to Trick 4 works out much worse for GIB), just that both West and East should make the same choices regardless of the card played from dummy to Trick 1, until the players play differently from each other.