Since 1992 the Lib Dems have won over 40 seats in four different elections.
And the SNP have won over 35 seats on two occasions.
When the SNP went high with 35 and 56, the Lib Dems scored low with 12 and 8.
When the Lib Dems scored high with 46, 52, 62 and 56, the SNP scored 6, 5, 6 and 6
And that is what would make it almost impossible for the Tories to win a majority, even if Labour falls short by 70 - 80 seats