My assumption is the fuzzy versions run through Google and the strict versions don't.
Yes, that's right. The fuzzy versions get their search results from Google, while the strict versions use their own (website) search functions.
For example, there's this artist who's sometimes recognized as Hikaru Utada
or Utada Hikaru
depending on the particular platform.
On the Deezer website, they have her (them?) as Utada Hikaru while in Genius and a couple of other sites, she's listed as Hikaru Utada.
So in the strict version of Deezer, I can't get any of her lyrics because she's listed as Utada Hikaru while I have her tagged as Hikaru Utada.
But in the fuzzy version, the Deezer provider will succeed because even when fed with either of those names, a google search will know exactly who I'm referring to.
Edit: so in short, the
- strict versions will have a slightly less number of matches than their fuzzy counterparts, but the lyrics returned will be as accurate as possible.
- fuzzy versions will have a slightly higher number of matches, but will consequently return incorrect lyrics at times - given how loose the search technique is.