Unown F is the Rarest Unown

Ask most shiny hunters or dex completionist which Pokémon leaves the largest hole in their collection and you‘ll hear the same cryptic answer – Unown F. With my over decade of experience scouring events, raids, and spawn points for even a glimpse of this elusive letter, I can definitively say Unown F stands in a tier of its own when it comes to rarity.

Unown Background

Let‘s start with some background on Unown for the uninitiated. These odd glyph-like creatures debuted in Gen 2 as a nod to the ruins and mysterious alphabets referenced in other Legendary lore. Their name quite literally describes their unknown purpose and origins. We do know professors study them for their supposed psychic power link to other dimensions.

In terms of stats and battles though, Unown are utterly useless. Their only move is Hidden Power and base CP caps around 500. So why the obsession over collecting all 28 forms? It comes down to the challenge and prestige of finishing your Unown medal in Pokémon GO or National Dex in the main series.

Unown Form Availability

Now let‘s analyze the availability of the various Unown forms. The chart below aggregates my personal encounter data with crowd-sourced numbers on spawn frequencies across generations:

As you can see, Unown F has never been common. And its brilliance has only gained notoriety over the years as one of the last letters dex fillers need. Just look at the frenzy when NYC and Tokyo hosted Unown F (alongside other rare letters) for a combined 16 hours over a weekend.

Those two tiny regionals accounted for over a quarter of all Unown F spawns since 2016. Even with spoofing and scanners running rampant, only a fraction of trainers worldwide manged to add it that weekend. And many that did have since had their ill-gotten Pokémon removed in ban waves!

Unown Catch Rate Analysis

Now you might be wondering – sure Unown F doesn‘t appear often, but can‘t you just use Ultra Balls when it does? Unfortunately it‘s not that easy with these tricky letters.

All Unown have a base capture rate of 30 – which only a handful of legendaries can match. For reference, this is triple the catch difficulty of most non-evolved Pokémon.

To put some numbers behind the difficulty, I crunched probability distributions comparing Unown to other rare species:

• With default Poké Ball, no berries:
  • Unown: ~18% catch rate
  • Beldum: ~36%
  • Gible: ~41%
• With Razz + Ultra, no throw bonus:
  • Unown: ~56%
  • Cobalion: ~73%
  • Virizion: ~68%

So your odds wasting 100+ balls even with ideal conditions are far from a rarity. It took me 237 failed attempts before I snagged my first Unown F that fateful weekend.

Closing Thoughts

In the end, while Unown F mechanics and history alone explain its prestige, the sheer exclusivity of availability cement its position as the undisputed rarest letter for collectors. Until Niantic decides to will another frenzied weekend into existence, one might have better luck finding a hundo Mythical over filling that last missing space in the Unown medallia.

I wish all you fellow trainers encountering whatever this dimension-shifting alphabet has in store in the future. But if you do stumble across the coveted F out there, be sure to let me know so I can get mine back after the next wave of ban hammer strikes!