Are starters guaranteed perfect IVs?

So I've been playing Pokemon Lets Go Eevee for a while now, and I unlocked the IV checker. I checked my starter Eevee's IVs and all of the stats say best on it. Am I guaranteed perfect IVs on my starter or am I just really lucky?

The starters in the Let's Go series are guaranteed perfect IVs. According to this guide, it's hardcoded as such in the game code, and the perfect IVs is also confirmed on Serebii.

In addition to having perfect IVs, the starters also have higher base stats compared to others in their species:

• Pikachu's base stats are 430 as opposed to 320
• Eevee's base stats are 435 are opposed to 325