In reply to Phil1919:
But you could only vote for the SNP in 50 odd seats out of more than 600.
Not sure what that's got to with it.
My comment was more to demonstrate how FPTP can favourably return seats to a particular party/parties, despite them having relatively low support compared to a party that only got one seat. It was also in response to mal_meech, who seemed to criticise FPTP for 'giving' the Conservatives more seats than they should have.
If PR had been in operation, how many seats would each party get? In particular, how many would PR's biggest advocate the Lib Dems have got...