We finish off our countdown of the biggest stories in racing with the saga that dominated the Formula 1 news agenda for much of 2019: the looming radical changes set to come into play in the 2021 season.

Motorsport.com's countdown of the biggest stories in racing in 2019 continues with Penske Entertainment taking over ownership of Indianapolis Motor Speedway, IndyCar and IMS Productions.

We're getting towards the business end of our Top Stories countdown now, and coming in at number three is the year of turbulence at Ferrari as Charles Leclerc gradually came to assert himself over Sebastian Vettel.

Motorsport.com's countdown of the biggest stories in racing in 2019 continues with McLaren’s stunning failure to qualify for the Indianapolis 500 with Fernando Alonso.

Kicking off the final five of our Top Stories countdown is the sudden end to Jorge Lorenzo's full-time MotoGP career.

Motorsport.com's countdown of the biggest stories in racing in 2019 continues with another that did not take place on the race track – the horrific plane crash involving former NASCAR driver-turned-analyst Dale Earnhardt Jr. and his family.

In at number seven in our Top Stories countdown is Citroen's decision to quit the World Rally Championship, and the 2020 driver market madness that preceded its announcement.

Coming in at number eight on our Top Stories countdown is a look back at how Honda transformed its reputation in Formula 1's hybrid engine era in the first year of its partnership with Red Bull Racing.

Motorsport.com continues its annual countdown of the biggest stories in racing with the future of NASCAR depending on the success of the Next Gen (aka Gen-7) car.

Kicking off the Top 10 of our countdown of the biggest stories in motorsport is seven-time NASCAR Cup Series champion Jimmie Johnson’s decision to make the 2020 season his last as a fulltime competitor.

We conclude the first half of our Top 20 stories countdown with one of the most memorable images of the Formula 1 season, which came courtesy of an irate Sebastian Vettel in Canada.

Not of all of Motorsport.com's Top Stories of the year concern events that played out on track, and today's entry is a classic of the genre - the long-running soap opera that was Rich Energy's sponsorship of the Haas Formula 1 team.