Does reduced trimming trump centering?

[GeoPoto]

If we start with a couple of assumptions that I think most will agree with:

(1) Centering is an important feature that contributes substantially to the attractiveness of a card; and

(2) It is preferable to collect cards that have not been trimmed, or at least have been trimmed less than most.*

*I am trying to avoid argument regarding the pervasiveness of trimming and whether a particular card has or has not been trimmed. I am also trying to avoid introducing other forms of alteration to focus on trimming. Snowman is an active spokesperson for the view that the only sensible perspective is that most attractive graded vintage cards have been trimmed and if you own one you have to assume it may have been trimmed. This leads to another factor in the attractiveness of a card: Does it look trimmed? Heavily trimmed? Lightly trimmed? Maybe not trimmed? Etc.

Below are four cards from one of my Washington back runs. The first one and the last one are well centered mid-grade examples. The middle two, though lower graded and less well centered, show more total top-and-bottom border, which would suggest less trimming, perhaps no trimming. The larger combined borders on the middle two also make it harder to look at the other two and not suspect that their superior centering stems at least in part from greater/better trimming.

So, I am interested in thoughts regarding how this phenomenon plays into card evaluation. If centering is vital to you (as it is to Snowman) do you elevate it above all else? Or do you prefer a card that, while not centered well, at least has borders that are large enough for you to believe it may not have been trimmed (much)? Do you reject a card that is perfectly centered but (appears) obviously trimmed?

The cards shown illustrate where I come out on this. The first one and the last one have enough border to (barely) support excellent centering. The middle two are regrettably off-center, but I love the larger (bottom) border. (Leon prefers big top borders and I would take it either way, although I do like an ample margin below the name.)

(Snowman: I hope you don't mind me leaning on some of your prior statements to frame this question. I hope to hear your thoughts on this as well.)

[ClementeFanOh]

George- Your scenario and questions are interesting. I'll begin by directly
answering the questions you asked:

1) Centering is the first attribute I notice on a card, but not the only one

2) Large border T206 don't bother me in the least

3) Yes, I would reject an obviously trimmed card

In regard to centering questions, the biggest issue I'm noticing is just how
often collectors mischaracterize it. You even did it yourself in the opening
post, when you referred to the middle examples as "off center". They aren't
off center, they just aren't perfectly centered. I wish I could recall the ID of
a member I was talking with privately a couple years ago. I owned a couple
T206 I described ad nicely centered, and he couldn't understand that a card
could be well centered/nicely centered without being "perfectly" centered.
The number of perfectly centered T206 must be miniscule indeed. If any of
you own T206 with 55/45 centering and are upset they aren't "perfect", I'll
take them off your hands

Trent King

PS- For the record, I like all 4 of your cards!

[Gorditadogg]

I like fat borders on T206s. I don't know if the skinny ones were trimmed or just cut that way, but the fat ones look better. I like the first card. The 2nd and 3rd don't fill out the holder and will probably rattle around. The 4th card is plus-sized, too, although not as nicely centered.

Sent from my SM-S906U using Tapatalk

[Eric72]

Originally Posted by GeoPoto

If we start with a couple of assumptions that I think most will agree with:

(1) Centering is a important feature that contributes substantially to the attractiveness of a card Regarding vintage cards, I believe centering is probably discussed more often than other characteristics. This might be due to the fact it's typically simple and straightforward. Even a relatively new collector can see and confidently discuss the centering of a vintage card.; and

(2) It is preferable to collect cards that have not been trimmed, or at least have been trimmed less than most.* Whether a card has been trimmed seems, to me like a "yes" or "no" condition. It either has been trimmed or it hasn't.

*I am trying to avoid argument regarding the pervasiveness of trimming and whether a particular card has or has not been trimmed. I am also trying to avoid introducing other forms of alteration to focus on trimming. Snowman is an active spokesperson for the view that the only sensible perspective is that most attractive graded vintage cards have been trimmed and if you own one you have to assume it may have been trimmed. This leads to another factor in the attractiveness of a card: Does it look trimmed? Heavily trimmed? Lightly trimmed? Maybe not trimmed? Etc.

Below are four cards from one of my Washington back runs. The first one and the last one are well centered mid-grade examples. The middle two, though lower graded and less well centered, show more total top-and-bottom border, which would suggest less trimming, perhaps no trimming. The larger combined borders on the middle two also make it harder to look at the other two and not suspect that their superior centering stems at least in part from greater/better trimming.

So, I am interested in thoughts regarding how this phenomenon plays into card evaluation. If centering is vital to you (as it is to Snowman) do you elevate it above all else? No, not above all else. Give me a 70/30 card with great color and registration over a blurry, washed out example that's DEAD CENTERED. Or do you prefer a card that, while not centered well, at least has borders that are large enough for you to believe it may not have been trimmed (much)? Do you reject a card that is perfectly centered but (appears) obviously trimmed? Again, to me, trimmed is a yes/no condition. It's like being pregnant. You either are or you aren't.

The cards shown illustrate where I come out on this. The first one and the last one have enough border to (barely) support excellent centering. The middle two are regrettably off-center, but I love the larger (bottom) border. (Leon prefers big top borders and I would take it either way, although I do like an ample margin below the name.)

(Snowman: I hope you don't mind me leaning on some of your prior statements to frame this question. I hope to hear your thoughts on this as well.)

.

[perezfan]

I like the sharp image of the first card best of the four. Sharp focus and registration is more important than centering to me any day of the week. It's the image of the central subject that matters most.

If there's any suspicion of trimming or "corrective" centering, I don't want it.

[GeoPoto]

Thanks for the responses. I wanted to weigh in regarding the issue: "Trimmed is a yes or no condition." and "if there is any suspicion of trimming, I don't want it."

This confuses me because it would seem to "define away" the key point I am trying to get at. My point wants to be that (almost) every purchase of a graded vintage card entails uncertainty regarding whether the card has been trimmed. Some look trimmed but might not be. Others sport robust borders, but who can rule out trimming? It seems to me that every card (I realize there are other factors involved in eye quality, but to focus on centering versus trimming) entails some tradeoff between how well it is centered and whether that centering (let alone edges) was achieved/enhanced via trimming.

If what you mean is some version of: "I don't buy high grade cards because I assume they are all trimmed, and I buy low grade cards that cost little enough that I don't sweat the possibility of trimming as much," I guess I could get that. But a "yes or no condition" seems to me to be an unrealistic standard in the marketplace.

For me, the examples I provided illustrate the tradeoff that exists in the marketplace: the centered examples (1 and 4) have just enough (any less and I would prefer a card that appeared less likely to have been trimmed) top and bottom border for me to accept the still significant risk that they may have been trimmed; while the "bottom heavy" examples (2 and 3) have just enough top border (any less and I would prefer a card with better top to bottom centering) for me to accept diminished centering in exchange for a very low probability of trimming (at least top to bottom).

[Luke]

I can't tell whether to take your words at face value, or if you're poking some fun at snowman, but none of your cards are trimmed. It's pretty easy to detect trimming on the vast majority of t206s. The only time it's tough is when the corners are sharp. Usually that means trimming, but not always.

To answer your question, if I am ever on the fence about whether a card in a numeric holder was trimmed, yes that affects how much I want it. I can usually tell one way or the other but there are occasionally some cards that leave me unsure based on looking at scans.

It's probably not very relevant to your question but I don't care that much about centering. I like rare cards and condition is down the list of things I worry about.

[brianp-beme]

Definitely T206 cards can be well-centered, have large borders AND have no trimming.

In my collecting world, centering is overrated. Give me good registration and color everyday. My favorite of the shown McIntyre Can-Can Dancing Trio is the card on the far right. It has decent color (not quite as good as the one in the center), but its registration is the best, and overrules any of its card flaws.

Not that I would kick any of the Can-Can Trio out of the revue.

Brian

[G1911]

Originally Posted by GeoPoto

Thanks for the responses. I wanted to weigh in regarding the issue: "Trimmed is a yes or no condition." and "if there is any suspicion of trimming, I don't want it."

This confuses me because it would seem to "define away" the key point I am trying to get at. My point wants to be that (almost) every purchase of a graded vintage card entails uncertainty regarding whether the card has been trimmed. Some look trimmed but might not be. Others sport robust borders, but who can rule out trimming? It seems to me that every card (I realize there are other factors involved in eye quality, but to focus on centering versus trimming) entails some tradeoff between how well it is centered and whether that centering (let alone edges) was achieved/enhanced via trimming.

If what you mean is some version of: "I don't buy high grade cards because I assume they are all trimmed, and I buy low grade cards that cost little enough that I don't sweat the possibility of trimming as much," I guess I could get that. But a "yes or no condition" seems to me to be an unrealistic standard in the marketplace.

For me, the examples I provided illustrate the tradeoff that exists in the marketplace: the centered examples (1 and 4) have just enough (any less and I would prefer a card that appeared less likely to have been trimmed) top and bottom border for me to accept the still significant risk that they may have been trimmed; while the "bottom heavy" examples (2 and 3) have just enough top border (any less and I would prefer a card with better top to bottom centering) for me to accept diminished centering in exchange for a very low probability of trimming (at least top to bottom).

It is a fact though. A card is either 1) trimmed or 2) not trimmed. There is no real possible status besides these two. It is a yes or no attribute, whatever ones opinion is.

Furthermore, trimming is usually (almost always, in hand) detectable with vintage cards. The natural size variance of T206 is not evidence that everything but the largest of cards are trimmed.

[sb1]

One of the key aspects of determining if a T206 has been trimmed or not is to learn what the edges should like, sizes will vary, original cuts will not. There are tell-tale signs of how the sheets were cut into vertical strips and then horizontally into singles, which if one handles enough of them, can learn what an original edge should look like.

A 10x loupe is generally all you will need.

[Eric72]

Originally Posted by sb1

One of the key aspects of determining if a T206 has been trimmed or not is to learn what the edges should like, sizes will vary, original cuts will not. There are tell-tale signs of how the sheets were cut into vertical strips and then horizontally into singles, which if one handles enough of them, can learn what an original edge should look like.

A 10x loupe is generally all you will need.

+1

This article by David Cycleback has been helpful to me. Hopefully, others will also benefit from it.

https://net54baseball.com/forum/content/trimming.html

[steve B]

Originally Posted by Eric72

+1

This article by David Cycleback has been helpful to me. Hopefully, others will also benefit from it.

https://net54baseball.com/forum/content/trimming.html

It really is an excellent article, hits the main points without getting too technical in the areas that are outliers.

One thing I will add, the rolled edge and corresponding ridge on the other side hold up even after major wear. That was a surprise to me years ago when I checked some of mine. Even cards well into the Poor to fair range clearly had those edge qualities.

There are a few ways an edge can look and be strange and not be trimmed. But they're mostly uncommon.

[Leon]

+1. Study of original cards is a great thing. That said, I always go for big borders too. I stay far, far away from high grade T206s with tiny borders. I am careful and feel very good about none of my (20+) T206s being trimmed.

Originally Posted by sb1

One of the key aspects of determining if a T206 has been trimmed or not is to learn what the edges should like, sizes will vary, original cuts will not. There are tell-tale signs of how the sheets were cut into vertical strips and then horizontally into singles, which if one handles enough of them, can learn what an original edge should look like.

A 10x loupe is generally all you will need.

[steve B]

To get back closer to the original topic, I've never been all that insistent about centering. Having it be sort of even is a plus, but a nice card that's not well centered is fine for me.

A nice card rejected for atypical cuts top and bottom, likely from a dull blade.

[Snowman]

All cards have been cut by a blade. Different blades produce different cuts. Variations in the sharpness of each blade produce variations in edge textures even within the same sets. If a 1954 Topps card was cut with one of the rotary cutters with a dull blade, then it produced cards with a rough cut. These were only used on the left and right edges of the cards though, as a different blade was used to cut them horizontally (ream cutters).

Here is a link below to an article on CU regarding the manufacturing process at Topps with several pictures of the process. Note there are also videos and other resources available online of the operations inside Panini and other card manufacturers.

https://forums.collectors.com/discus...opps-cut-cards

If you believe that you can spot the majority of trimmed cards with a loupe, you're wrong. Especially with modern cards. You can learn how to detect a botched edge or a bad trim job, but you absolutely cannot detect a good one and neither can the most experienced graders at every TPG. And if you think AI is going to help with that, you'd be wrong again.

That said, you can certainly tell when certain cards have been trimmed. I encounter them regularly. But those were all trimmed by amateurs. It's like hair transplants. You can't detect a good one, only the bad ones. There are a lot of people walking around with hair transplants and you just don't know it. I wonder what there's more of, trimmed cards or people with hair transplants? I'd bet it close. Both are certainly in the millions.

As far as how to approach the market as a buyer, I think what the OP is getting at is that there is often no way of truly knowing whether or not a card has been trimmed. If it bothers you enough then you should probably study the subject, perhaps even cut up some cards yourself with various blades and examine them with a loupe so that you know what you're looking at. Then approach each card you encounter as having a likelihood of being trimmed or not rather than a "yes" or "no" determination. Cards with rounded corners are usually safe, cards with sharp corners that don't measure correctly are often not. If it's a PSA 9 or 10 vintage card and the borders look small, then it was almost certainly trimmed (and there are A LOT of these cards out there). Maybe take the Leon approach and only look for cards with large borders (although even large cards are not always safe). You can easily slice off 1/128" from a card. So if a card measures even just 1/32" tall, that means someone could trim it 4 times and still be within spec. And if you think rough cuts are safe, think again. This example below from a BODA post should tell you nearly everything you need to know about the trimming scandal. Note it measures the same size in both images.

As for me personally, I generally don't want trimmed cards unless it's a high-end card that I wouldn't otherwise be able to buy. Or rather I should say I don't want cards that bear evidence of trimming. I'm sure there are cards in my collection that were trimmed undetectably (we all have them), but as long as they measure correctly and the edges look like factory cuts, then I probably wouldn't care if I were to find out that it was trimmed. But I definitely try to avoid trimmed cards to the extent that it's possible.

[Snowman]

The funny thing about the Clemente above is that Moser put the rough cuts on the wrong edges lol. Seems like he would know that too. I wonder if he was trolling PSA/the hobby when he chopped that one up?

PSA says it's still good though lol

https://www.psacard.com/cert/26928973

[steve B]

The cutters used have varied over the years. I doubt the same machine would be used in 91 that was used in 55. And Panini and other manufacturers use an entirely different process now.

I have doubts about the picture shown for cutting in that article. Especially since some of the others are staged and not actual production. Hand feeding one sheet at a time into a machine is so slow it wouldn't work. The machine she's got is too narrow to fit the sheet that's there, and the bookcase next to it isn't leading anywhere.
That it's a staged photo on a different machine isn't surprising. The collating machines were a trade secret, and wouldn't be shown in a public article. They may not have even been collated at Topps, I don't recall the date, but in the 90's a company was advertising secure cutting and collating services in the Thomas Register.

The claim that nobody can detect a good trim job is just plain wrong. Lets put an end to that. Could it be hard given the few seconds the TPGs spend? Yes. Undetectable? No.

[Leon]

A lot of times we differ in our thinking. But I think this post of yours is spot on, conerning trimming. Any really good grader will say it's not an exact science. OF course there are telltale signs, but it's not 100%, nor can it be.

Everything you said, is true, from what I know. No doubt a card with huge borders could still be trimmed. But the chances are much, much lower. And, I am biased, but still think pre war cards with big borders, and not likely trimmed, will gain more as the hobby matures. I am fairly confident this Duffy hasn't been trimmed, but can't ever be 100%.

Originally Posted by Snowman

All cards have been cut by a blade. Different blades produce different cuts. Variations in the sharpness of each blade produce variations in edge textures even within the same sets. If a 1954 Topps card was cut with one of the rotary cutters with a dull blade, then it produced cards with a rough cut. These were only used on the left and right edges of the cards though, as a different blade was used to cut them horizontally (ream cutters).

Here is a link below to an article on CU regarding the manufacturing process at Topps with several pictures of the process. Note there are also videos and other resources available online of the operations inside Panini and other card manufacturers.

https://forums.collectors.com/discus...opps-cut-cards

If you believe that you can spot the majority of trimmed cards with a loupe, you're wrong. Especially with modern cards. You can learn how to detect a botched edge or a bad trim job, but you absolutely cannot detect a good one and neither can the most experienced graders at every TPG. And if you think AI is going to help with that, you'd be wrong again.

That said, you can certainly tell when certain cards have been trimmed. I encounter them regularly. But those were all trimmed by amateurs. It's like hair transplants. You can't detect a good one, only the bad ones. There are a lot of people walking around with hair transplants and you just don't know it. I wonder what there's more of, trimmed cards or people with hair transplants? I'd bet it close. Both are certainly in the millions.

As far as how to approach the market as a buyer, I think what the OP is getting at is that there is often no way of truly knowing whether or not a card has been trimmed. If it bothers you enough then you should probably study the subject, perhaps even cut up some cards yourself with various blades and examine them with a loupe so that you know what you're looking at. Then approach each card you encounter as having a likelihood of being trimmed or not rather than a "yes" or "no" determination. Cards with rounded corners are usually safe, cards with sharp corners that don't measure correctly are often not. If it's a PSA 9 or 10 vintage card and the borders look small, then it was almost certainly trimmed (and there are A LOT of these cards out there). Maybe take the Leon approach and only look for cards with large borders (although even large cards are not always safe). You can easily slice off 1/128" from a card. So if a card measures even just 1/32" tall, that means someone could trim it 4 times and still be within spec. And if you think rough cuts are safe, think again. This example below from a BODA post should tell you nearly everything you need to know about the trimming scandal. Note it measures the same size in both images.

As for me personally, I generally don't want trimmed cards unless it's a high-end card that I wouldn't otherwise be able to buy. Or rather I should say I don't want cards that bear evidence of trimming. I'm sure there are cards in my collection that were trimmed undetectably (we all have them), but as long as they measure correctly and the edges look like factory cuts, then I probably wouldn't care if I were to find out that it was trimmed. But I definitely try to avoid trimmed cards to the extent that it's possible.

[Snowman]

Originally Posted by steve B

The claim that nobody can detect a good trim job is just plain wrong. Lets put an end to that.

What makes you believe that? You sound confident.

[steve B]

Originally Posted by Snowman

What makes you believe that? You sound confident.

I am confident. Every manufacturing process leaves evidence of itself.

it isan exact science.

A guillotine cutter and a home or even pro paper cutter will leave a different cut. A sharp blade leaves a different cut than a dull one. Die Cutting which is used for most modern cards is different than any of them. Same for rotary shears.
The only exception I'd make to detectable or not would be using a professional guillotine cutter on cards produced using that type of cutter. And that has some very real challenges if you're trying to trim an individual card.

Size doesn't really matter, within limits. What matters is edge quality and placement. The edges ae also directional.
You were very close with the rough edges on a trimmed card being in the wrong place. I would bet that those edges are not in the correct direction

[Gorditadogg]

AI is going to take all our jobs, except PSA grader. It won't be able to do that. OK.

I think it would be fascinating to have a contest at one of the shows sometime where the top card experts could identify trimmed cards. We could get several cards that have been outed by BODA, and mix them in with others with known provenance, that we know came straight from packs to slabs. The contestants could look at all the cards with their loupes, and say which ones were trimmed. At the end of the show the actual trimmed cards would be revealed.

Sent from my SM-S906U using Tapatalk

[Leon]

I politely disagree with being able to identify trimming, as an exact science. No grader I have ever spoken with (and I have spoken to many) say it's an exact science. Take your factory guillotine cut cards, cut a sliver off with an exacto knife, and rub your finger over the edges. There is no way to tell it was cut, period. And nothing anyone says will convince me otherwise.

Just my opinion and everyone has their own ideas. I only base mine on experience.

Originally Posted by steve B

I am confident. Every manufacturing process leaves evidence of itself.

it isan exact science.

A guillotine cutter and a home or even pro paper cutter will leave a different cut. A sharp blade leaves a different cut than a dull one. Die Cutting which is used for most modern cards is different than any of them. Same for rotary shears.
The only exception I'd make to detectable or not would be using a professional guillotine cutter on cards produced using that type of cutter. And that has some very real challenges if you're trying to trim an individual card.

Size doesn't really matter, within limits. What matters is edge quality and placement. The edges ae also directional.
You were very close with the rough edges on a trimmed card being in the wrong place. I would bet that those edges are not in the correct direction

[Gorditadogg]

Originally Posted by Leon

I politely disagree with being able to identify trimming, as an exact science. No grader I have ever spoken with (and I have spoken to many) say it's an exact science. Take your factory guillotine cut cards, cut a sliver off with an exacto knife, and rub your finger over the edges. There is no way to tell it was cut, period. And nothing anyone says will convince me otherwise.

Just my opinion and everyone has their own ideas. I only base mine on experience.

What if Steve and Greg entered that contest at the card show and both nailed 20 out of 20. Would you still not be convinced?

Sent from my SM-S906U using Tapatalk

[steve B]

I've seen a display of altered stamps that were good enough I couldn't spot the alterations. Those were miles ahead of any trimming I've seen.

I would be open to being tested. if someone sent a common or two, with or without known trimming to keep it from being just a hunt for what I would know is there, I believe I could find a trim nearly every time.

Could I do it in 30 seconds like the grading companies take? I'm not sure.

I would be open to similar tests for any alterations. Some of the borderline ones where some think it's altering some don't may in fact be undetectable some of the time. Like wiping off a wax stain.

[Leon]

For the same reason I don't cut strips of cards, or already damaged cards, I wouldn't want to test your abilities. I am sure you would do very well. That said, I just reaffirmed with a grader whom I happen to know, he doesn't think trimming is an exact science either. I am quite sure any good grader will say the same thing. That doesn't mean they don't catch a lot, or most, of the alterations. I think they do. But there are some things I just don't think they can detect. And I am not talking about higher grade cards. I am talking the 2s-5s ranges....which will have normal, handled, wear.

To Al above, if they got 20 of 20 right, I would have to re-eavaluate my position

Originally Posted by steve B

I've seen a display of altered stamps that were good enough I couldn't spot the alterations. Those were miles ahead of any trimming I've seen.

I would be open to being tested. if someone sent a common or two, with or without known trimming to keep it from being just a hunt for what I would know is there, I believe I could find a trim nearly every time.

Could I do it in 30 seconds like the grading companies take? I'm not sure.

I would be open to similar tests for any alterations. Some of the borderline ones where some think it's altering some don't may in fact be undetectable some of the time. Like wiping off a wax stain.

[Snowman]

Originally Posted by Gorditadogg

AI is going to take all our jobs, except PSA grader. It won't be able to do that. OK.

I think it would be fascinating to have a contest at one of the shows sometime where the top card experts could identify trimmed cards. We could get several cards that have been outed by BODA, and mix them in with others with known provenance, that we know came straight from packs to slabs. The contestants could look at all the cards with their loupes, and say which ones were trimmed. At the end of the show the actual trimmed cards would be revealed.

Sent from my SM-S906U using Tapatalk

It's funny you say that because I'm actually working on putting together a kit of random cards with various alterations to send out to people who want to test their skills and see what they can and cannot detect. We can start a list for anyone who wants to take the test and just pass the cards on from one person to the next. Then I'll reveal the answers at the end.

[Snowman]

Originally Posted by steve B

I am confident. Every manufacturing process leaves evidence of itself.

it isan exact science.

A guillotine cutter and a home or even pro paper cutter will leave a different cut. A sharp blade leaves a different cut than a dull one. Die Cutting which is used for most modern cards is different than any of them. Same for rotary shears.
The only exception I'd make to detectable or not would be using a professional guillotine cutter on cards produced using that type of cutter. And that has some very real challenges if you're trying to trim an individual card.

Size doesn't really matter, within limits. What matters is edge quality and placement. The edges ae also directional.
You were very close with the rough edges on a trimmed card being in the wrong place. I would bet that those edges are not in the correct direction

Yes, of course there are differences in cuts from each of the various blades you mentioned and how dull or sharp they are. If you cut a card with the wrong type of blade, it will obviously stand out. What you seen to be overlooking though is that you cannot distinguish between two cards that were cut by two different guillotine blades or two cards that were cut by two different ream cutters, etc. There simply isn't that much variation in edge textures of cards to begin with. It's very easy to duplicate most cuts. Hell, you can even buy the same cutting machines that were used by Topps. There's a reason these guys are getting trimmed cards through by the thousands. It's because they're not detectable unless they're amateurs who completely botch the cards up.

[Snowman]

Originally Posted by Gorditadogg

What if Steve and Greg entered that contest at the card show and both nailed 20 out of 20. Would you still not be convinced?

Sent from my SM-S906U using Tapatalk

I'd award them each ten grand if they could identify even 5 out of 20

[G1911]

Originally Posted by Snowman

I'd award them each ten grand if they could identify even 5 out of 20

If you start honoring your bets and send Jeremy his $10K, I'll take you up on this offer.

[steve B]

Originally Posted by Snowman

I'd award them each ten grand if they could identify even 5 out of 20

Send me 20 and lets see.

There are sets that would be very hard, and I don't think I could tell reliably. Ramlys, T51, other very thin cards.

Send 20 cards, probably best if they're commons. (or 10 or 30 , whatever, as long as it's not hundreds or thousands...)
There can be any number of them trimmed, as long as you know which ones, or even if it's all or none of them.
Maybe send the list beforehand to a third party, and third party. So someone else has the identical info. Me not knowing and someone else knowing keeps us both honest.

That's an open offer to anyone.
Unlike some, while I don't like being wrong, I'm ok with it if it can be proven.

[GeoPoto]

To the extent that this discussion has progressed to a very specific dispute regarding how reliably an experienced detective can correctly determine whether a card has been trimmed, I would like to point out that it has gone beyond the dilemma I was trying to point out. The world I live in is limited to looking at AH images and deciding whether the card offered is an "upgrade" to my collection or not. This forum has taught me to be leery of TPG grades and authentications. Common sense (and Leon) offers the notion that larger borders correlate with reduced probabilities of trimming. From there it's a short leap to the tradeoffs involved in choosing between well centered cards with skimpy borders and less well-centered cards with meaty borders.