Well, the results are in (with the exception of one constituency). The question posed was "What will the Conservative majority be, or if no majority, what seat deficit would they have to a majority?" The election result was:
And our guesses were:
The Conservatives needed to attain 326 seats to achieve a majority, and as they can now only attain 318 seats, or 319 if they retain Kensington, they have a deficit to a majority of 8 seats, or 7 seats if they retain Kensington.
As the returning officer for The Port Forum 2017 First General Election Sweepstake I hereby declare that Ian sweeps the lot, with his guess of -7.