Historically, the golden rule of betting on Tory leadership races was to lay the early favourite. Only in 2019 - a contest set amid unique circumstances - did that favourite deliver, with Boris Johnson.
These races invariably take many twists and turns, involving various tactical manoeuveres. The parliamentary party has been described as the most sophisticated electorate in the world. Whoever leads after tomorrow's first round ballot is by no means certain to stay there.
Latest odds: 2.942/1
So should we be laying Rishi Sunak? He was a short-odds favourite long before the vacancy became open. Despite a major drift to double-figure odds when his reputation took multiple hits, the gamble restarted in earnest after last week's resignation.
The campaign launch was predictably slick and doubtless prepared for months. Team Sunak have already announced 39 nominations to take a clear lead. This is the standard for a front-runner, as ambitious colleagues jump aboard in hope of a good job. This is only stage one, however.
Sunak has to address two big problems. First, every other candidate is running on tax cuts, against the tax rises he already imposed. This is a terrible position to hold among any Conservative electorate. It partly explains why he fell so sharply in the ConservativeHome ratings.
Second, weekend press briefings made it clear that Boris Johnson's team blame Sunak for his demise. #Sunakthesnake and #NeverRishi were trending on Twitter. He's bound to struggle to win over Johnson supporters.
The positive is that he polls better than the rest against Labour. Whether that trend survives through TV debates and a vicious campaign, remains to be seen. I expect Sunak to make the final, but lose.
Latest odds: 3.7511/4
For months, Mordaunt has been my main pick. Despite never being truly in the frontline of government, she has soared up the members' polls on ConservativeHome. Last week they recorded her losing only one potential head-to-head run-off - against Ben Wallace, who is not running. In yesterday's poll, she led the field.
That is seriously impressive given her scope for growth in recognisability. Critically, Mordaunt is less associated with Johnson. She didn't back him in 2019 and has only held minor roles in his government, well below her Defence Secretary status under Theresa May.
She has been quietly making all the right moves for months, courting powerful US Conservative interests and nailing her colours to a Republican Party agenda.
Never underestimate the ideological and financial crossover between UK and US Conservatives. Identifying those links worked a treat to pick both Iain Duncan Smith and David Cameron in past races. During the 2019 leadership contest, Donald Trump blatantly intervened, pushing Johnson and sleighting his principal rival, Michael Gove. Few complained. Many laughed.
Mordaunt of course isn't the only candidate building those networks and the case to back her is much wider. She is an impressive speaker and has the perfect profile for a Tory contest. A young, strong woman who served in the Navy. A strong Brexiteer, on the Right of the party, with reported substantial support from the 2019 intake of MPs.
Latest odds: 5.04/1
Frequently derided by critics of the Tory party, yet evidently loved by the membership, as seen in approval ratings. Her Thatcher idolatry may be mocked on Twitter, but Truss knows how to appeal to her electorate.
Six months ago, it was widely said that the contest would boil down to Sunak v Truss. She has been planning this run for years. Which makes her opening tally of 15 nominations appear a worryingly weak effort.
Without dismissing Truss by any means - I think she could beat Sunak in a run-off - there is a danger she could suffer from overcrowding among right-wing candidates. Suella Braverman has stolen her thunder on the Northern Ireland Protocol. Kemi Badenoch too. Were Priti Patel to enter, it could leave three out of four candidates short of nominations.
Latest odds: 12.5
The Chairman of the Foreign Affairs Committee has started well and is in third place regarding nominations. He's now very well positioned among the relatively moderate wing of the party, which was excluded by and often opposed to the Johnson administration.
This veteran of the Afghanistan conflict oozes gravitas on the Parliamentary stage and has long struck me as very electable. His work exposing the Londongrad laundromat was outstanding and never more prescient.
A problem could ultimately be his image as being a relative moderate, even on the Left of the party. That seems like a small minority nowadays, especially among members. He voted Remain in the 2016 referendum, which will be a disqualifier for many.
That I like Tugendhat, probably implies Tory members won't be too keen. I think he'll start well but hit a ceiling and turn out to be a more competitive version of Rory Stewart's 2019 bid. The Tory that non-Tories, without a vote in the contest, want to win.
Latest odds: 16.015/1
I must confess, in years of studying this market, Kemi Badenoch never crossed my mind. She's now up to fifth place in the betting, following the endorsement of Michael Gove. More dramatically, she ranked second in yesterday's ConservativeHome poll.
Were she to win, it would rank as the biggest upset in political betting history, or at least on a par with Jeremy Corbyn winning the 2015 Labour contest. That proves outsiders can win these races, as David Cameron also proved a decade earlier.
I have no doubt she has big potential as a Cabinet Minister, or that there is an audience for her libertarianism, or that she would make a useful weapon in the 'War on Woke'. But surely this is way too soon for the former Equalities Minister? She hasn't been scrutinised, or even road-tested as a candidate. Tory MPs do not take big gambles with their choice of leader.
Again though, qualification for latter rounds would cause problems for others.
Latest odds: 50.049/1
Distant runner-up to Johnson in 2019 and that was perhaps only due to tactical swaps to block a stronger rival in Gove.
Hunt has been poor value throughout. He's never fared well with members and any credentials rested on support from MPs. That this so-called 'Big Beast' has a mere 13 nominations suggests otherwise. Lay and lay again. He is not the winner.
Latest odds: 100.099/1
The former Health Secretary launched his bid today. He was immediately questioned about his former non-dom tax status, and failed to satisfactorily answer or kill the question.
Is it too late anyway? On the latest count, with half of the parliamentary party declared, he has only 11 nominations and needs 20 by 6pm on Tuesday. I suspect he's chasing the same pool as Tugendhat and Hunt.
To only have ten, Javid must be struggling. He's long been expected to run, as in 2019, especially after triggering Johnson's downfall by resigning. His ConHome ratings aren't encouraging either.
Latest odds: 55.054/1
Likewise the new Chancellor's late entry, amid a stream of allegations about his finances and tax affairs, looks like a bad plan, too late.
Zahawi has been close to Johnson for years, so he could appeal to the remaining loyalists. He's on 15 nominations, so 20 by tomorrow is not impossible. If he does get in, there is scope for improvement as he handles the media well.
Latest odds: 120.0119/1
The Attorney General was first out of the blocks in declaring a bid. She swiftly earned the considerable endorsement of Steve Baker - defacto head of the ERG and now her campaign manager. He is a very shrewd, effective operator.
She's on 11 nominations and probably won't qualify. However if she does, I think the membership will love her and her presence in later rounds could make life very difficult for Truss and even Mordaunt.
Latest odds: 200.0199/1
If ability to handle the media, and speak in a conversational style, were the sole criteria, Shapps would be favourite. Yet he has only seven nominations.
He's a former arch-Remainer and has stated that he's not the man for the 'war on woke'. That explains why he's a rank outsider.
Latest odds: 500.0499/1
Just as people started complaining about too many candidates, the MP for Gillingham and Rainham entered the fray. This, and the fact he's a junior Foreign Office Minister, are all I know for sure about Chisti. I've seen him on TV a few times, without ever thinking about leadership potential. It will be an enormous shock if he merely gets enough nominations.
Back Penny Mordaunt @ 3.7511/4