3 (State of Origin, Bledisloe Cup)
In 36 Origin series: Queensland 21, NSW 13, drawn two. Using the first match as a proxy for a one-game Origin: Queensland 18, NSW 18.
5 (Ashes cricket, MLB division series)
Assuming one team is favoured against an opponent 60/40, the difference in win probability for favourites from a three-to a five-game series is 64.8 percent to 68.3 percent.
7 (NBA and NHL Play-offs, MLB League Championship and World Series)
Only six comebacks from 3-0 in history of best-of-seven: four in ice hockey, and one each in baseball and NBA.
13 (America’s Cup 2017)
Premier yacht race has been contested over 13-, 17-, three-, nine- and seven-race series since WWII, having seen both big sweeps and crazy comebacks.
23 (World Snooker Championship rounds played…