Because of the volume of cards and variants, its hard to document all the changes between the early design and the final design. But many of the changes could be interesting or enlightening.
For example, if you’ve every tried to do an original 151 binder, you’ll come into a problem that some Pokemon appear in Base and Jungle/Fossil. So what’s the canonical “real” version of the card?
Take Electrode, that shows up in Base and Jungle. This is the “beta playtest” version - which has one of each of the 151 represented.
Basic artwork: Red/Green Sugimori stock images for Pokemon, trainers have Ooyama/Kinebuchi artwork. 70 Pokemon / 13-30 Trainers. Cards would end up in Base set
Similar looking to Delta Playtest but with different artwork (CD Promo for Venusaur/Charizard/Blastoise). I have seen 3 others: Pikachu (Black Star), Mewtwo (Base), Clefairy (base)
The Alpha Prototype design is simply a flipped sprite from Red/Green
Alpha Playtest Sugimori artwork would of course be selected for base with this sunset background
Beta Playtest Sugimori artwork wouldn’t be used until JP “Gym Heroes” in '98, skipping Team Rocket which used Himeno’s artwork.
Minor change to hit points 30 > 40 after alpha prototype. This is interesting, perhaps preliminary playtesting occurred before alpha playtest, 30 HP was just too low?
No changes to the attack: “Pound” はた, (1) energy cost, 10 damage
Alpha Prototype is not “colorless” type but instead 竜 type, meaning “Dragon”. Switching to colorless makes sense as there were only three dragon pokemon then.
Both Alpha and Beta Playtest note that Dratini is 伝説のポケモン, “legendary pokemon” in the Pokemon Characteristics Box at the bottom right corner. The final design would keep the same Pokedex entry but would remove calling it a legendary pokemon.
Would be cool to see the full presentation set if anyone has a link. I like the experimentation with backgrounds. I like to think of this as the ‘Windows XP’ zard.
The Alpha and Beta Chanseys stat wise are very similar. The Beta artwork was only ever used in the Evolution box of Aquapolis Blissey. The differences I see are the changing of the Level from 12 to 55 and the clarification that resistance is -30.
They also clarified in Beta that the second attack Double - Edge does 80 damage to itself (my translation might be wrong but I think the Alpha just says something like “does equivalent damage to itself”?
What I find interesting are that Alpha & Beta are both already pretty nerfed from the Creatures Deck Ooyama Chansey (guess we have to give up Beta Chansey as a name for that one lol), which has 140 HP and the Double - Edge attack does only 50 damage to itself not 80. Also there is no resistance feature. So the Ooyama have been created pretty early.
" Windows XP is a major release of Microsoft’s Windows NT operating system. It was released to manufacturing on August 24, 2001, and later to retail on October 25, 2001 ."
Is there any lore yet on why we went from Sugimori to Sugimorori between the Alpha Playtest and Beta Playtest cards? Or was it simply a random typo which then got copy/pasted 151 times over? They corrected it in subsequent releases so no harm done in the end. These being internal test objects, and all.
The conundrum posed by pfm is definitely a nice one. You could argue that these very playtest cards are the real canonical version of the card. It is a sort of 0th edition 151, although never released to the public. Until now, I guess.
I’ll now analyze the 13(3)7est Pokémon, being Porygon:
Let’s start with the obvious: the Alpha Playtest version is our Base Set Porygon except for 4 minor differences:
“CG” in the Data box changed to its katakana form of “シージー”.
The general updated layout for the attack and flavor text boxes.
The illustrator change from Ken Sugimori to Tomoaki Imakuni.
Swapping the position of Weakness and Resistance.
Some changes occurred between the Alpha and Beta Playtest version:
Artwork got swapped out for a different pose and removed the background.
A floating letter “g” appeared above the “チ” in “テクスチャー1”.
“CG” in the Data box changed to its katakana form of “シージー”.
The “ダメージ-30” text next to the Resistance was removed.
The Ken Sugimorori typo was added. (not unique to this card)
If I missed any, feel free to add them below!
All in all it seems they had a really good grasp on what Porygon was going to look like considering how miniscule the changes are between the playtest versions and its final Base Set release.
@pfm FYI, there are also three “Beta Presentations” up for auction.
Here is Charizard for example. It’s the Alpha Playtest Pokemon with a background. Didn’t know if you wanted to add this info to your nice summary post.
Regarding the Clefairy. Apart from the Alpha Presentation and Beta Presentation you’ve mentioned above, as well as the Alpha Playtest and Beta Playtest:
Honestly, since that has such a low CGC number when compared to the rest, I think the Clefairy with the colored background is really just the Delta Playtest. I think they got this wrong or didn’t know Delta was a thing originally. If true, not a good look for CGCs authentication process.
Poliwhirl has similar differences with Dratini and other prototypes.
Alpha Prototype is a flipped sprite from Green version.
Alpha Prototype HP increased from 50 to 60.
Something interesting in the Alpha Prototype is the weakness and resistance - Strong against Water, Fire, and Ice attacks. (Half); Weak against Water and Grass attacks. (Double). This implies an Ice typing was cut for the final version. It is not a new discovery as information about cut types has been noted in a few informational posts on social media about the prototypes but cool nonetheless and I thought I’d mention it here in case anyone reading this had not noticed that.
Alpha Playtest art is very pixelated.
Beta Playtest art would not appear until the next appearance of Poliwhirl in Gym Heroes.
Some wording/verbiage was changed to be more succinct in the Beta Playtest e.g.
Forget
Choose one of the opponent’s Pokémon’s “Moves.” That “Move” cannot be used during the opponent’s next turn.
Double Slap
Flip 2 coins; this attack does damage equal to the number of heads ×30.
changes to
Forget
Choose one of the opponent’s “Moves” and prevent it from being used in the next turn.
Double Slap
Flip 2 coins; this attack does 30 damage times the number of heads.
Poliwhirl remains a tadpole Pokemon throughout and its description doesn’t change.
If anyone sees an Alpha Playtest Poliwhirl come up for sale please reach out to me EDIT: I found one.
As @Matt151 already stated, CGC completely missed the ball on this one. It’s not a Beta Playtest, nor is it a Delta Playtest. It would appear to be an Alpha Presentation version.
All the Playtest cards have a Kanji inside the circle next to the Pokémon’s HP, whereas all the Presentation versions have the Energy Symbols that are still in use to this day.
Why Alpha Presentation and not Beta Presentation?
Alpha Presentation:
Floating “g” error.
Black Kanji " 抵抗カ" next to the Resistance Symbol (~ Resistance Force)
Resitance Symbol above Weakness Symbol.
Low detail text.
Slim Bold “HP+Value” & Illustrator Name.
Slim Bold Separation Lines between Attacks, Flavor Text and Illustrator Zones.
What is the correct colour of blue??? The evolution box gets darker from Stage I to Stage II, which is what is seen on other cards too. But what background is correct?
PWCC/Goldin seem to be the closest match. I also think they might be more true to the colours since we also see the lighter blue around the art box as much more distinct. Happy to hear from anyone who may actually be a graphic designer
Have any prototype Trainer or Energy cards been graded and/or sold? I know we’ve seen photos of them in magazines and such, with those interesting checkerboard patterns.
EDIT: I found one. 
