Mike Derry holds a commanding 95% implied probability in the Calgary-Shaw by-election market because the riding has consistently favored the United Conservative Party, which captured 56% in the prior general election. Derry secured the UCP nomination in June after defeating a sitting city councillor, gaining endorsement from Premier Danielle Smith and positioning the party to maintain its suburban Calgary base ahead of the September 14 vote. Advance polls opened this week with limited reported shifts in sentiment. The main challenger, NDP candidate Kyle Campbell, faces structural headwinds in a historically conservative district. Late developments such as unusually low turnout, unforeseen candidate controversies, or coordinated opposition surges could narrow the margin, though current trader pricing indicates these remain low-probability outcomes.