Politics punters have seen upsets in Batley and Spen and Chesham and Amersham this year but there are signs that the next big surprise could be in Germany next month. If it comes to pass, it will certainly have bigger ramifications than any British by-election.
Armin Laschet is the firm favourite on the Betfair Exchange to become Germany's next chancellor after the federal election on 26 September but the polling, and reporting from the country, indicates that it is by no means a certainty.
Angela Merkel's 16 year chancellorship will end in six weeks. Only Otto von Bismarck and Helmut Kohl ruled Germany for longer and it is possible we will never again see a leader of a major political power achieve something comparable.
The momentousness of Merkel's departure could be lost amid the uncertainty that's likely to follow an election that looks less predictable by the day. The new government could be formed by an unstable three-way coalition.
Next month's election is a huge moment, not just for Germany but for the whole of Europe, as it will determine who is in charge of the continent's biggest economy and who plays arguably the most influential role at the EU.
Laschet is Merkel's heir apparent - he is the centre right candidate for the Christian Democratic Union - and he is 1.351/3 (a 74% chance) to be next chancellor on the Exchange.
And yet, even for an experienced figure like Laschet, it is never easy to follow a political giant - just ask John Major or Gordon Brown. This might be one reason why on the campaign trail Laschet looks lacking in confidence and gaffe-prone.
A few weeks ago, he was caught on camera laughing during a visit to flood victims. This week he made a fool of himself alongside Elon Musk at a Tesla factory near Berlin.
Markus Soeder - the leader of the CDU's Bavarian sister party the CSU, whom Laschet narrowly beat to win the bloc's nomination for chancellor - is openly critical of Laschet and calls his campaign unconvincing.
One German pollster observed: "Never since 1949 has a federal German election been so open."
Electoral system favours Laschet
Other candidates for chancellor are eclipsing Laschet in the polls with Olaf Scholz - the centre-left Social Democratic Party candidate - this week getting 44% in a poll which asked Germans for their preferred chancellor, compared to 21% for Laschet.
Scholz is in to 5.04/1 to be next chancellor but he has been backed at around 275.00.
Clearly the momentum is with Scholz who has reversed his party's decline even if they are 9.417/2 to take the most seats.
Annalena Baerbock of the Green Party, that could have a big say in who governs Germany after the election and go into coalition, got 16% when it came to preferences for next chancellor.
The Greens and SDP were level on 19% in the over all polling while the CDU is on 26%. In the end, the CDU's strength, in spite of doubts about its candidate, could be the biggest factor in determining the outcome.
The CDU has only been out of power for 20 out of 72 years in the history of the German republic. Like the Conservatives in the UK, it sees itself as the party of power and, when it comes to winning elections, it generally knows how to get the job done.
The chancellor, like the British prime minister, is not directly elected. Were the chancellor elected in an American style presidential system then Laschet would be in der scheisse.
As it is, he is the leader of Germany's biggest political bloc and it is 1.182/11 to win the most seats on 26 September. Laschet's backers are banking on him scraping to power at the head of a shaky coalition.
Make no mistake, though, this is a far more open German election than many commentators, and CDU supporters, expected it to be when Laschet was anointed as Merkel's would-be successor earlier this year.