I had to google this because I just had a hand where the BBO Double Dummy tool was clearly wrong. South led the 7H, I covered 10H, North played 4H, and DD said regardless of the card played by North, the hand was good for 3NT +2. It clearly isn't or I've lost my marbles. If North covers the 10H with the QH, the contract goes down at least 1. [hv=pc=n&s=sqj85haj873dj3c86&w=sak2ht2d98754cq32&n=st97hq94dkcjt9754&e=s643hk65daqt62cak]399|300[/hv]