This Graph Explains the Importance of Turnout to the outcome of the Election Tomorrow.
If Turnout is the 72.2% of the Brexit Referendum last year you can see that the Light Blue line shows That the middle third of the probability distribution curve on Ashcroft's polling numbers has a Tory Majority of between 20 and 60 seats.
The 2015 turnout was 66.1 % overall. around the same as 1997 general election less than the 77% for the 92 vote. Historically the 1950 and 51 elections had over 80% turnouts.