It used to be that Pokemon used the built-in memory on the card to save the game, but with Pokemon Sword and Shield it works differently, as it's stored directly on the Switch. If you want to start a new game, here's what you need to do:
- On the Switch home screen, go to system settings, which is the Cog icon.
- Scroll down the System Settings menu screen to the Data Management tab.
- On the right options, scroll down where you should find Delete Data.
- Find and select Pokémon Sword or Pokémon Shield in your list of games, then select Delete save data for (Profile name)
- A warning message will appear asking if you are sure you want to delete it and confirm once it allows you to.
Be warned. As with previous games in the series, this is a permanent deletion, and all Pokémon in this save, regardless of location (team or storage), will all be lost and unrecoverable. If you want to keep any Pokémon from save to save, you'll either need to transfer them to a friend for safety or consider using Pokémon Bank to store it, although the latter requires a subscription.
Additionally, if you received a Mew from the Poké Ball Plus feature and placed it in-game, you will not be able to get another one. So address to remove it with caution if you want to keep your Mew.
You can also play the game on a different profile on your Switch, as this will create a separate set of save data in your main profile. However, if you do not have a Nintendo Account online, you will not be able to use the game's online features.
