Every year, teams in F1 recruit raw talent from the junior series to race for them in hopes of having better drivers. These young drivers are then signed by the top teams on the grid in the following seasons if their talent is well enough for them.
However, it has happened multiple times that new F1 drivers have switched teams in the middle of a season, usually upgrading to a better team where their racecraft could help them get victories and even world championships.
Here are three F1 world champions who made their debut with a junior team and then moved on to a different team mid-season:
#1 Michael Schumacher - Jordan to Benetton F1, 1991
Michael Schumacher made his F1 debut with Jordan in 1991, replacing Bertrand Gachot, who was imprisoned at the time.
However, after the Belgian Grand Prix of the season, he had disagreements with the team and moved to Benetton for the rest of the season. He went on to win two world championships in 1994 and 1995 with them.
#2 Sebastian Vettel - BMW Sauber to Toro Rosso, 2007
Sebastian Vettel replaced Robert Kubica in BMW Sauber after the Canadian Grand Prix to drive for them.
However, he was later signed by Toro Rosso to race from the Hungarian GP onwards, as he was already under contract with Red Bull. He then became the youngest race winner at the time with the team and then went on to win four consecutive world championships with Red Bull.
#3 Max Verstappen - Toro Rosso to Red Bull, 2016
Max Verstappen was signed by Toro Rosso in 2015 and drove excellently for the team. Mid-season in 2016, his talent was recognized by Red Bull and the team decided to sign him as their permanent driver. He replaced Daniil Kvyat in the team and did what he was expected to, win. He debuted with the team from the Spanish Grand Prix and won the race with ease.
Although he was assisted by the fact that the two Mercedes drivers Lewis Hamilton and Nico Rosberg took each other out on the first lap, his drive was no less of excellence. He has been with the team since and has won two world championships and is on the chase to win his third consecutive.