What would be a good night for Labour in the local elections? It’s a trickier question to answer this year than last year, as the map is about as tricky for Labour as it could possibly be, even if you ignore – as for the purposes of this piece I’m going to – the polls and poor council by-election performances.

There are 88 councils up for grabs, of which 34 are in England, 32 are in Scotland, and 22 are in Wales. All of those are “all up” – council areas where all the councillors are elected in one go every four years. Local authorities in Wales and England elect councillors using first-past-the-post, while in Scotland, they use the single transferable vote.

Of the 32 in Scotland, Labour is expected to suffer further losses to the SNP. These councils were last contested in 2012, when Labour was still riding high in the national polls. Labour took control of two councils and kept control of Glasgow and Edinburgh. Four out of 32 doesn’t sound like great but thanks to Scotland’s proportional system they actually control more councils than any other party north of the border. Quite a lot has changed for Labour in Scotland since 2012 so no-one expects anything other than a pasting.

However, a “good night” – such as it is – would be one which showed that the Conservatives cannot beat Labour into second place when Ruth Davidson, currently the most popular politician in Scotland according to the polls, is not a candidate.

In Wales, again, these seats were last contested in 2012, the peak of Ed Miliband’s popularity. Labour on a good night would make some gains here and the thing to watch out for is how they do in areas where Ukip and Plaid Cymru did well in the Assembly elections in 2016. All the evidence is that Plaid Cymru are doing surprisingly well despite being an unapologetically pro-Remain party in a country that voted narrowly to Leave, so keep an eye out for that. Ukip have declined significantly in the polls since May 2016, and in Wales, that helps Labour. But, of course, when these seats were last contested, Ukip had yet to experience their 2013 surge, so there is less good news for Labour there.

A good night would be one in which Ukip failed to advance, and in which Labour outperformed its 2016 showing on them. Also worth watching are the Welsh seats that went Conservative in 2016 – Gower, Vale of Clywd, which were Labour-held, and Brecon and Radnorshire, which was a Liberal Democrat seat – and what happens there.

In England, it is also a tricky map for Labour, though that these were last contested in 2013 means that they are coming off a worse performance than they had in Wales and Scotland. Don’t forget, too, that Labour is well below its previous peak in opposition as far as council seats are concerned, and still has less than it did mid-way through the New Labour period, when years in office had worn away at its local government base.

That said, the map is still fairly tricky. Their best opportunities – their “home games” if you will” are metropolitan boroughs, and just one, Doncaster, up this May.

Of the six unitary authorities up for grabs, just Durham and Northumberland are in areas where Labour is competitive. In Durham, the party holds 94 out of 126 seats. There is some room for further growth but not much. In Northumberland, a good night would see the party take majority control in a local authority where it is currently the largest party.

In the remaining four councils – the Isle of Wight, Shropshire, Wiltshire, and Cornwall – the traditional battle is between Conservatives and Liberal Democrats, though the latter party took a pounding in the coalition years. (The Isle of Wight’s largest grouping is now independent councillors.) A good night for Labour would see the Liberal Democrats continue their revival here, where they are the only plausible threat to the Conservatives.

Then there are the 27 county councils, again, most of which are not particularly happy hunting grounds for Labour even in wave years. On a good night, the party would win a majority in Nottinghamshire, where it is one short of a majority, become the largest party or even gain control in Staffordshire and Warwickshire, and consolidate its position in Derbyshire and Lancashire councils. Elsewhere, the prospects for gains are slim and the main hope should be, again, for the Liberal Democrats to revive in the places they can hurt the Tories.

In addition, there are seven directly-elected mayoralties up for grabs. They use the supplementary vote system – if no candidate achieves more than half the vote on the first round, the top two go through to an instant run-off and the second preferences of the remaining candidates are redistributed.

Of those mayoralties, one – Cambridgeshire and Peterborough – would remain Conservative unless Labour were on course to win power in a landslide. Labour should, likewise, win at a canter in the Greater Manchester, Liverpool City Region, Doncaster, North Tyneside and Tees Valley races.

The two competitive elections are the West Midlands, which both Labour and the Conservatives have hopes of winning, and the West of England, which is the only three-way marginal of the new mayoralties: any of the Conservatives, Labour, or the Liberal Democrats could win it. So on a good night, Labour would take the two marginal mayoralties while winning its home bankers as well.

Overall, while it is never a good sign for the opposition to lose seats and for the government to gain them, a "good night" for Labour on this map would be one in which the opposition parties make gains overall and the Conservatives fall back overall, rather than simply making gains themselves.

Now read: what would be a good night for the Lib Dems in the 2017 local elections?