[THUNDERDOME] Calling all opinionated coin graders to duke it out in the comments

AlbumNerd

Calling on all opinionated coin graders, your help is requested!

It's been a blast building out my AI coin grading and identification app these past two weeks. Folks here have given a lot of great feedback and I've made numerous updates to Numi since.

A key part of Numi's logic is that it references detailed grading criteria I've compiled based on the top TPG's public grading standards. Whenever Numi is asked to grade a coin, it references these grading standards to make a final estimated grade.

I've been running around to various coin shops to talk with dealers to get their feedback on the wording of Numi's grading criteria, but I'm getting a lot of mixed messages. One coin shop dealer said, "Anything above an MS-65 should have absolutely zero markings or damage. The main criteria should be strike strength, luster, and eye appeal.". However the next day another dealer told me, "Markings and damage are totally ok for some MS-65 and MS-66 coins."

So now I want to turn to the wisdom of the crowds. I'm looking for opinionated coin graders on this forum to share their thoughts on Numi's grading criteria.

Below is what Numi currently uses:

GRADING DEFINITIONS & CRITERIA
Key grading aspects to consider when running your analysis

Surface Check: Evaluate for cleaning, alterations, and environmental impacts like corrosion.
Edge/Rim Review: Examine for irregularities like dings, nicks, or filing.
Strike Analysis: Assess the evenness and completeness of strike quality, focusing on traditionally weak areas.
Error/Variety Detection: Identify any notable errors or varieties.
Eye Appeal: Assess overall aesthetic, including coloration and luster. [i.e. Red, Red Brown, Brown, etc]
Historical Context: Consider the coin’s history and rarity when applicable.

Mint State (MS): Focus on the absence of wear, strike sharpness, and original luster preservation.
Proof (PR): Focus on the mirrored finish, hairline absence, and strike sharpness.

MS/PR 70: Absolutely flawless. Full, undisturbed luster with no handling marks. Fully struck with zero damage.
MS/PR 69: Virtually perfect, with only minuscule imperfections visible. Fully struck, sharp detail, and luster is completely undisturbed. Extraordinary eye appeal.
MS/PR 68: Near flawless. Almost no weakness in the strike. Full radiant luster. A few tiny imperfections are barely visible. Eye appeal is exceptional.
MS/PR 67: Only the slightest weakness in the strike. Radiant luster. Minor imperfections are visible. Outstanding eye appeal. No marks or hairlines are visible.
MS/PR 66: Well struck. Full luster. Few marks or hairlines, and not in focal areas. Excellent eye appeal.
MS/PR 65: Above average strike and mostly full luster. Minor marks or hairlines are visible, mostly out of focal areas. Great eye appeal.
MS/PR 64: Average or slightly better than average strike. Luster is bright. Few small scattered contact marks or hairlines, though none severe.
MS/PR 63: Average or slightly weaker than average strike. Luster is bright. Moderate marks or hairlines.
MS/PR 62: No wear. Average or below average strike. Luster is possibly impaired but better than 61. Numerous marks or hairlines.
MS/PR 61: No wear with a slightly below-average or weak strike. Multiple heavy marks or hairlines.
MS/PR 60: No wear. Weak or poor strike. Numerous heavy marks or hairlines, as well as noticeable spots or color inconsistencies.

About Uncirculated (AU):Focus on wear on high points, original luster preservation, and clarity of design details.
AU 58:Full details. Miniscule wear on high points. Almost mint state appearance with full luster.
AU 55: Full details. Minimum wear on high points. Considerable remaining luster.
AU 53: Full details. Minor wear on more than 50% of the design. Some luster remains. Minimal softness on high points.
AU 50: Full details. Slight wear on more than 50% of the design. Bits of luster remain. Minor softness on high points.

Extremely Fine (XF): Focus on noticeable wear on high points and partial luster retention.
XF 45: Minimal loss of details. Light to minor wear on high points. Some luster may still remain in protected areas.
XF 40: All details elements are still visible. High points are worn flat. Miniscule luster may still remain in protected areas.

Very Fine (VF): Focus on wear on the general surface and design detail softening.
VF 35: All major details visible. Minuscule wear on the entire surface. Miniscule luster may still remain in protected areas.
VF 30: Miniscule flattening and minuscule loss of some details in major design features. Minor wear on the entire surface. No luster remains.
VF 25: Minor flattening and minor loss of some details in major design features. Minor wear on the entire surface. No luster remains.
VF 20: Moderate flattening and moderate loss of some details in major design features. Moderate wear on the entire surface. No luster remains.

Fine (F): Focus on overall wear and flatness, with major design details still apparent, especially in recessed areas.
F 15: Sharp and clear lettering. Slightly less than half of the finer details are worn flat.
F 12: Lettering remains visible but not as sharp and clear. Slightly more than half of the finer details are worn flat.

Very Good (VG):Focus on worn major designs and lettering, finer detail loss, and prevalent surface flatness.
VG 10: Considerable wear has flattened most of the finer details. Most lettering remains readable. The rim is full.
VG 8: Considerable wear has flattened almost all of the inner details. Some inner lettering is still visible. The rim is full.

Good (G): Focus on mostly complete peripheral lettering and heavily worn major design elements, with still distinct rims.
G 6: Full rim and peripheral lettering but the design is now flat and visible only in outline form.
G 4: Rim is mostly full but may be flat or slightly worn into peripheral lettering in spots. All lettering is still readable.

About Good (AG): Focus on the identifiability of main design elements, with rims blending into the fields and legible lettering.
AG 3: The coin is significantly flat. The rim is worn into the tops of lettering and fields. Most lettering is still readable.

Fair (FR): Focus on flatness, minimal details, peripheral and discernible lettering.
FR 2: The entire coin is worn flat. Very few details remain. Only traces of peripheral lettering are still visible.

Poor (PO): Focus on the identifiability of coins by type and date.
PO 1: The entire coin is worn flat. Only enough details remain to be identifiable as to the coin's date, type, and mintmark.

I would love to start a discussion and see what you believe should be changed. I have also created a public Google doc with these criteria for easier sharing and commenting. I'll update Numi's logic based on the discussion here and continue to test the app with graded slabs.

This continues to be a wonderful community. Thank you all for the feedback you've shared so far. Let's see if we can continue making coin collecting more approachable.

• Album Nerd/Dansco Dude

p.s. I recently updated Numi to v1.30 alpha to include PCGS integration. You can find more detailed update notes here. I was also recently interviewed by the Coin World Podcast about Numi. If you'd like to learn more about the inner workings of Numi and how Artificial Intelligence is used, I went into more detail there.