There are only 9 Mario Kart games. It's only 10 if you count Mario Kart 8 twice, since it got a rerelease on Switch. And this includes the mobile MK game for Android/IOS. There are 13 Ratchet and Clank games, with a 14th coming out this year. And this doesn't count rerelease of Size Matters. So 15 if we are counting rereleases. In 2007, the Mario Kart and Ratchet series were tied with 5 releases each. Mario Kart as a series started in 1992, Ratchet in 2002. Sony released 5 games in 5 years while Nintendo released 5 games in 10 with 2 of them being on handhelds. In total, Sony released have 40% more Ratchet games in 50% less time.