by Dr Adrian Worton
Last time we ran through the seats in Northern Ireland to kick off our General Election coverage. We still can't do the whole country as we only have data on 398 seats. However, like Northern Ireland, all 40 Welsh constituencies are covered, so we can delve into those.
Last time we ran through the seats in Northern Ireland to kick off our General Election coverage. We still can't do the whole country as we only have data on 398 seats. However, like Northern Ireland, all 40 Welsh constituencies are covered, so we can delve into those.
With more than double the number of seats than in Northern Ireland, this won't be as in-depth, but it will still allows us to look for general trends.
Expected holds
In Northern Ireland, 9 seats (i.e. half) saw the incumbent favourite to win the seat with over a 99% probability. No such seats exist in Wales. This seems to be because the seats with the highest majority are all Labour-held, and the bookmakers generally do not seem favourite towards Labour.
Below are the seats where the incumbent has at least an 80% chance of retaining their seat:
Expected holds
In Northern Ireland, 9 seats (i.e. half) saw the incumbent favourite to win the seat with over a 99% probability. No such seats exist in Wales. This seems to be because the seats with the highest majority are all Labour-held, and the bookmakers generally do not seem favourite towards Labour.
Below are the seats where the incumbent has at least an 80% chance of retaining their seat:
The slide away from Labour can be seen by contrasting the margins and the probabilities. For example, Labour had a 11,412 majority in Islwyn, whilst Plaid Cymru had a wafer-thin 92 majority in Arfon. However, both parties have the same probability of holding the seats, at 96.9%.
Similarly, a 314 Conservative majority in Preseli Pembrokeshire gives a 89.8% chance of victory, compared to 89.3% in Ogmore, where Labour's majority last time was 13,871.
Assuming these seats are indeed held, this gives Labour 17 seats, the Conservatives 4 and Plaid 3.
Weak favourite
Next up are the seats where the favourite has more than 60% chance of winning the seat:
Similarly, a 314 Conservative majority in Preseli Pembrokeshire gives a 89.8% chance of victory, compared to 89.3% in Ogmore, where Labour's majority last time was 13,871.
Assuming these seats are indeed held, this gives Labour 17 seats, the Conservatives 4 and Plaid 3.
Weak favourite
Next up are the seats where the favourite has more than 60% chance of winning the seat:
I've included Vale of Clwyd in this list, despite the favourite having an 88.1% chance of winning, as it fits in with the general theme of Conservative gains. Despite a relatively high Labour majority of 2,379, the Conservatives are strongly expected to gain this seat. They are also favoured to overturn four-figure majorities in Newport West and Wrexham.
Aberconwy is listed as Independent, but the Conservatives won it at the last election; since then the MP (Guto Bebb) had the whip removed.
Montgomeryshire has long been a two-way battle between the Conservatives and the Liberal Democrats, and with the latter surely set to improve from their terrible showings in 2015 and 2017, they may make this a closer contest, although they are second-favourites here. They are fancied to claim Ceredigion from Plaid, who in turn may take Ynys Mon from Labour.
Of a list of 8 constituencies, 5 of which are currently held by Labour, they are predicted to only keep one: Bridgend.
Marginals
Now onto the seats where the favourite has less than 60% chance of winning:
Aberconwy is listed as Independent, but the Conservatives won it at the last election; since then the MP (Guto Bebb) had the whip removed.
Montgomeryshire has long been a two-way battle between the Conservatives and the Liberal Democrats, and with the latter surely set to improve from their terrible showings in 2015 and 2017, they may make this a closer contest, although they are second-favourites here. They are fancied to claim Ceredigion from Plaid, who in turn may take Ynys Mon from Labour.
Of a list of 8 constituencies, 5 of which are currently held by Labour, they are predicted to only keep one: Bridgend.
Marginals
Now onto the seats where the favourite has less than 60% chance of winning:
First off is Brecon and Radnorshire. This seat saw a by-election just three months ago, where the Lib Dems took the seat from the Conservatives. The Lib Dems were aided by Plaid and the Green Party standing aside, and they are doing so again this time. However, this time an electoral pact is expected to favour the Conservatives, as the Brexit Party are standing aside for the Conservatives. They claimed 3,331 votes in August, which would be enough for the Conservatives to reclaim the seat.
Contrary to the figures shown above, Vale of Glamorgan should be a Conservative hold. An error on the site we get our values has the Lib Dems listed as 1/200, very generous given that they aren't standing in this seat.
The remaining six seats - all Labour held - are all roughly neck-and-neck. Given that the final vote will almost-certainly see a swing towards one party or the other, it is likely that all six will be won by the same party.
Conclusion
Ignoring the marginal seats listed above, Labour are favourites in 18 seats and the Conservatives in 10. It doesn't seem out of the question that the Conservatives will roughly equal Labour's seats tally in Wales, although Labour are favourites to take the most seats. In an area that is traditionally very Labour, these values represent the concerns surrounding Labour's ability to get votes in its traditional heartland.
Next time we'll look at Scotland. No prizes for guessing who the best-performing party will be there, but instead it is worth asking - how well will the SNP do?
Contrary to the figures shown above, Vale of Glamorgan should be a Conservative hold. An error on the site we get our values has the Lib Dems listed as 1/200, very generous given that they aren't standing in this seat.
The remaining six seats - all Labour held - are all roughly neck-and-neck. Given that the final vote will almost-certainly see a swing towards one party or the other, it is likely that all six will be won by the same party.
Conclusion
Ignoring the marginal seats listed above, Labour are favourites in 18 seats and the Conservatives in 10. It doesn't seem out of the question that the Conservatives will roughly equal Labour's seats tally in Wales, although Labour are favourites to take the most seats. In an area that is traditionally very Labour, these values represent the concerns surrounding Labour's ability to get votes in its traditional heartland.
Next time we'll look at Scotland. No prizes for guessing who the best-performing party will be there, but instead it is worth asking - how well will the SNP do?