Use Base Set Unlimited Price to Determine the 1st Edition Price Range - MATH 101

Hey All, I decide to share some info on how to check if the Base Set 1st edition Holos are overpriced or underpriced based on the Unlimited Set price movement.

Everyone has a feeling some cards are undervalued or overvalued, but how much over, or how much under? what is the reasonable price range for the cards?

Here I demonstrate a method to determine the reasonable price range for the base set 1st edition holos based on the price movement of the unlimited versions. This method can be extended to fossil , rocket, jungle, you name it, it just works.

In general, this is a way to determine the Low-Frequency Prices by using the High-Frequency sales.

Step 1: Normalize the price for both 1st edition and unlimited. There are different ways to normalize the data, you can pick the min-max scaler, or try turning the data into normal distribution, different ways will provide different results, I can write a whole page on this, DM me if you want more details.

Step 2: Calculate the 2-sigma bound for the unlimited price. Similar to stocks, theoretically, 95% data should be within the bound, but in practice, I only found around 87%-92% within the bound.

Step 3: Once we get the upper bound and lower bound, apply the same bound to the 1st Edition Prices, reverse calculate the possible upper and lower price range for the 1st edition.

Conclusion: Now we can get a reasonable short term price range for the 1st edition cards. I backtested this method, on average over 75% hit the target.

Examples 1: (Base Set Unlimited Blastoise PSA 8 to determine 1st Edition PSA 8 price)


The Blue and Black Lines are the 2-sigma bounds, The red line is the 1st edition price, blue line is the unlimited price, redline’s movement is guided by the 2 bounds.

Blastoise: Based on the data from 2022-May. The final price prediction for early June would be: Upper Bound: $2235, Lower Bound: $1320 with a 74.55% chance within this range.

Examples 2: (Base Set Unlimited Charizard PSA 8 to determine 1st Edition PSA 8 price)

Examples 3: (Fossil Unlimited Moltres PSA 9 to determine 1st Edition PSA 9 price)

Moltres: Based on the data from 2022-May. The final price prediction for early June would be: Upper Bound: $307, Lower Bound: $183 with a 70.67.% chance within this range.

Any questions or suggestions to this method are greatly welcomed. You can also DM me for more details. Thanks.

7 Likes

You are much too smart for me to understand any of this, so I’m just going to give you my credit card and trust you’re on to something!

3 Likes

Are you normalizing the data between 1st ed and unlimited independently? It’s way more correlated than I would have thought

I’d love to know how to do this yourself please haha

Hey sorry I just saw the message. The hardest part I believe is managing and cleaning the data, for example, how can we get all the Team Rocket PSA 9 Unlimited Dragonite Holo #5 price over the past 2 years. once we have clean data, the rest is just standard math, I believe a lot of people can do better than this, I’m not smart, but this model still works like magic, very good method to check if a WOTC card sales are in a reasonable price range and provide a price prediction in a short period of time ahead.

If you would like to check the details, I would love to discuss the details with you.

1 Like

Im a number theorist so nice seeing this kind of thread. Would be nice seeing a list of overvalued to undervalued. Maybe just base set for now but feel free to show as much as you want to. You showing the undervalued cards if any will cause them to spike in future data lol.

Could you tell us the range for 95% certainty? I am very interested in this data.

Hey Jac, sure, I don’t think this post is going to cause any spike to the market, I’m just a small person in the hobby. But just in case, I will only cover the data up to July-31st, so the model can provide some information for earlier this month, which already passed, I’m not going to cover this month data, just to minimize any potential influence. if you’re interested in this part, we can DM.

The following is the results for the 1999 1st edition Base Set, you can check if it matches the market in early August. The over or undervalue price range is only valid for early Aug, this model can’t provide any long-term pricing.

Edit: I forgot to mention the Upper bound and Lower bound below are the reasonable price range calculated from the model.

PSA 9:
Blastoise PSA 9: (2022 July) Latest Price: $3038.0 #### Upper Bound: $5439.78 #### Lower Bound: $3593.95 #### Detect: Undervalue
Mewtwo PSA 9: (2022 July) Latest Price: $2499.0 #### Upper Bound: $2303.48 #### Lower Bound: $1033.48 #### Detect: Overvalue

PSA 8:
Nidoking PSA 8: (2022 July) Latest Price: $611.0 #### Upper Bound: 500.69 #### Lower Bound: 207.47 #### Detect: Overvalue
Clefairy PSA 8: (2022 July) Latest Price: $510.0 #### Upper Bound: 360.54 #### Lower Bound: 154.87 #### Detect: Overvalue
Ninetales PSA 8: (2022 July) Latest Price: $750.0 #### Upper Bound: 647.33 #### Lower Bound: 194.14 #### Detect: Overvalue
Poliwrath PSA 8: (2022 July) Latest Price: $449.44 #### Upper Bound: 354.5 #### Lower Bound: 203.18 #### Detect: Overvalue
Alakazam PSA 8: (2022 July) Latest Price: $1000.0 #### Upper Bound: 844.47 #### Lower Bound: 307.61 #### Detect: Overvalue
Hitmonchan PSA 8: (2022 July) Latest Price: $561.0 #### Upper Bound: 396.51 #### Lower Bound: 237.88 #### Detect: Overvalue
Chansey PSA 8: (2022 July) Latest Price: $650.0 #### Upper Bound: 567.56 #### Lower Bound: 287.78 #### Detect: Overvalue
Gyarados PSA 8: (2022 July) Latest Price: $835.0 #### Upper Bound: 551.27 #### Lower Bound: 330.38 #### Detect: Overvalue
Mewtwo PSA 8: (2022 July) Latest Price: $1100.0 #### Upper Bound: 974.95 #### Lower Bound: 528.98 #### Detect: Overvalue

Conclusion: (July) I will not touch PSA 8 1st editions, my model might be wrong, but a lot of 1st edition PSA 8 are overvalued. especially that Gyarados PSA 8.

(July) Base Set PSA 9 are within the reasonable price range except Blastoise a bit undervalued and Mewtwo a bit overvalued, PSA 9 seems fine and healthy to me.

1 Like

Yes, we can do 95%, but that will expand the price range intervals making the range a bit too wide. like the min=$5, max=$500, which is not very useable. I usually the number that equals the back test success rate.

For each card, the model detects a separate range. and they are all difference. would you like to specific which card you would like to check?

Nice thanks. I wonder which cards are over and under from other wotc sets. Base set is stable in 9s i wonder if there are any extreme cases anywhere else.

Are you able to predict all kinds of cards or just ones with 1e/unlimited variants?

How would it work for modern cards raw/graded? Or is there just a lack of data?

The Following are for 1st edition Holo cards only,

For the 1st edition jungle set,

Mr Mime PSA 9: (2022 July) Latest Price: $220.0 #### Upper Bound: $169.04 #### Lower Bound: $56.03 #### Detect: Overvalue
Vileplume PSA 9: (2022 July) Latest Price: $130.0 #### Upper Bound: $109.73 #### Lower Bound: $61.97 #### Detect: Overvalue

For the 1st edition Fossil set,

Zapdos PSA 9: (2022 July) Latest Price: $217.5 #### Upper Bound: $190.12 #### Lower Bound: $134.95 #### Detect: Overvalue

Team Rocket is a bit different; I have around 13k recent sales record for 1st edition, but only 7k unlimited sales, seems like 1st edition is much more popular, so this method doesn’t really work on all the cards except the Dark Blastoise, Dark Charizard and Dark Dragonite.

Dark Blastoise PSA 9: (2022 July) Latest Price: $530.0 #### Upper Bound: $512.85 #### Lower Bound: $341.36 #### Detect: Overvalue

Dark Charizard and Dark Dragonite are all within the reasonable price range.

For the Neo sets, this method doesn’t work since the number of Unlimited sales are not enough to support the algorithm. I’m confident to use this method on base set, fossil, jungle and some team rocket card, the rest of WOTC needs some other type of math to get the predictable price range.

Overall for July 2022–>early Aug, the WOTC PSA 9 holo prices are ok, just some slightly overvalued and a few slightly undervalued, seems like people tend to overpay than underpay.

1 Like

In general, this method uses the high frequency data to check/ predict low frequency data, so there has to be multiple variations of the same card, like 1st edition/unlimited. So, it won’t work on modern cards

But for general prediction, it is possible, I used some Neural network stuff and trained as hard as I can, and the output is ok.

I didn’t dig deep into this since I don’t really believe in actual number prediction, that’s why I came up with this method to provide a predictable price range.

for the second question,
I think it would be difficult to do this for raw cards. Unlike Graded cards, there are hardly any standards for the raw cards condition, which of course determines the value. So, I think would be best to use this model under the graded cards category.

now you mentioned this, I might be able to build a massive card price prediction model and share some insights as I develop it along the way, prob can make it public, but not sure how many people are interested in these stuff…lol

3 Likes