Despite Labour having huge majorities across the city, the SNP are now only 5/2 to win all seven seats in Glasgow next May.
This market is a good indication of why we don’t usually allow accumulators on constituency betting. Normally, you’d multiply up the odds from each individual proposition to provide a price on all of those things occurring. If you did that with the SNP odds in each of the Glasgow seats, you’d get odds of just under 40/1, as opposed to the 5/2 that Ladbrokes are actually offering.
In bookies’ terms, this is known as a “related contingency”; the chances of the SNP winning each of the Glasgow constituencies are not independent and so just multiplying up the odds doesn’t provide a true price for the accumulator. Basically, if they win Glasgow North East, which is the only one Ashcroft had them trailing in, they will almost certainly have won all of the six easier seats as well. So the odds on a clean sweep are only a little better than those on them winning just that one, hardest, target.
We’ve also got some revised odds on how many seats the SNP will win across Scotland. They hold six at the moment but are currently favourites in 40 of the individual constituency markets.