Playing in the bridgez tourney, I was doing very well until I got a near-bottom on the last board of the 16-board tournament:
After the robot North opened 2C and rebid 2H, I knew that we were headed towards 3NT. But 3NT should do better being played with the strong hand hidden, so I decided to temporize by showing my 5-card club suit. Bad mistake, as the robot now put me in the no-play slam.
10% on the last board cost me at least two places in the final rankings, but it didn't drop me below the Wbridge5 robot.
So, on to my list of bad predictions, goes the title of this post.