STAR can handle any number of candidates because it's a Cardinal system. Meaning that you count the ratings independently. You can rate as many candidates as you want at 5 stars. Or Zero stars, or anything in-between.

That right there is the reason it's immune to the spoiler effect.

It also makes it, not immune to tactical voting, but resistant? Tactical voting exists, but using it actually gives you worse results. Your best results come from just being honest with your preferences.

Which is almost unheard of in voting systems.

Every other major voting system penalizes you for being honest.

[–] davidagain@lemmy.world 1 points 2 days ago

It's unclear to me what you think I have misunderstood.

(The fractional voting system penalizes you for being dishonest, but it's not a major voting system and doesn't pass the person-in-the-street trusts it test.)