 Complete the following phrase:  Del Potro has a record against Roger Federer. They have met in 6 finals, all at ATP World Tour 500 Series level or higher, with del Potro leading 42; besides the US Open title he also captured both 2012 and 2013 Swiss Indoors finals and the 2018 Indian Wells final, while Federer has won finals against del Potro at the 2012 Rotterdam Open and the 2017 Basel Open. Del Potro also won their biggest match to date in 5 sets at the 2009 US Open final, shortly after Federer won their next most important match in 5 sets at the 2009 French Open semifinals a few months before. Federer also won the longest best of 3-set match in the history at the 