BGS Grading: Centering, Corners, Edges, and Surface

In previous blog posts I've discussed how a card's final Beckett Grading Service grade (BGS grade) can sometimes be more than 0.5 higher than the lowest subgrade.

Remember, the general rule is that a card's final grade can only be 0.5 higher than the lowest subgrade, unless two or more of your subgrades share the lowest subgrade score then your final grade will be equal to that lowest subgrade.  (See this blog post for more information about the general rule.)

But when one subgrade is drastically lower than the rest of the subgrades, the card's final grade can sometimes be 1.0 higher than the lowest subgrade.  However, this exception to the general rule only applies to the edges and surface subgrade.

The Exception to the General Rule

A card's final BGS grade can be 1.0 higher than the lowest subgrade if: (1) the drastically lower subgrade is either the edges or surface; and (2) the aggregate of the other three subgrades compared to the surface subgrade must be greater than 4.

Below are some cards to illustrate these exceptions.

Surface

The general rule is that the card's final grade can only be 0.5 higher than the lowest subgrade; however, in the above Aaron Rodgers card the final grade is 1.0 higher than the surface subgrade.  This is because the lowest subgrade is the card's surface subgrade, and the aggregate difference of the other three subgrades when compared to the surface is 5 (the math is (9-7) + (8-7) + (9-7) = 5), which is greater than 4.

Again, the general rule is that a card's final grade can only be 0.5 higher than the lowest subgrade but in the above Jose Abreu card the card's final grade is 1.0 higher than the lowest subgrade.  That is because the lowest subgrade is surface, and the aggregate difference of the other three subgrades when compared to the surface is 4.5 (the math is (10-8.5) + (10-8.5) + (10-8.5) = 4.5), which is greater than 4.

The general rule is that a card's final grade can only be 0.5 higher than the lowest subgrade.  In the above Cordarelle Patterson card the card's final grade is only 0.5 higher than the lowest subgrade.  This card follows the general rule because although the lowest subgrade is surface, the aggregate difference of the other three subgrades when compared to the surface is 4.0 (the math is (9.5-7.5) + (8.5-7.5) + (8.5-7.5) = 4.0), which is not greater than 4.

The general rule is that a card's final grade can only be 0.5 higher than the lowest subgrade.  In the above Tom Brady card the card's final grade is only 0.5 higher than the lowest subgrade.  This card follows the general rule because although the lowest subgrade is surface, the aggregate difference of the other three subgrades when compared to the surface is 3.5 (the math is (9-8) + (9-8) + (9.5-8) = 3.5), which is not greater than 4.

Edges

A card's final BGS grade can be 1.0 higher than the lowest subgrade if: (1) the drastically lower subgrade is either the edges or surface; and (2) the aggregate of the other three subgrades compared to the surface subgrade must be greater than 4.

The general rule is that the card's final grade can only be 0.5 higher than the lowest subgrade; however, in the above Dan Marino card the final grade is 1.0 higher than the edges subgrade.  This is because the lowest subgrade is the card's edges subgrade, and the aggregate difference of the other three subgrades when compared to the edges is 5.5 (the math is (8.5-6.5) + (8.5-6.5) + (8-6.5) = 5.5), which is greater than 4.

The general rule is that the card's final grade can only be 0.5 higher than the lowest subgrade; however, in the above Matt Barkley card the final grade is 1.0 higher than the edges subgrade.  This is because the lowest subgrade is the card's edges subgrade, and the aggregate difference of the other three subgrades when compared to the edges is 6.5 (the math is (9.5-7) + (9.5-7) + (8.5-7) = 6.5), which is greater than 4.

Centering

The exception that the card's final grade can be 1.0 higher than the lowest subgrade if the lowest subgrade is edges or surface does not also apply if the lowest subgrade is centering.  In other words, even if the centering subgrade is drastically lower than the rest of the card's subgrades, the card's final grade will still be only 0.5 higher than the lowest subgrade.

The general rule is that the card's final grade can only be 0.5 higher than the lowest subgrade.  In the above Reggie Wayne card, the final grade is 0.5 higher than the lowest subgrade.  This is because the lowest subgrade is the card's centering subgrade.  Although the aggregate difference of the other three subgrades when compared to the centering is 5.5 (the math is (9-7.5) + (10-7.5) + (9-7.5) = 5.5) which is greater than 4, that still doesn't matter because the lowest subgrade is centering.

Corners

The exception that the card's final grade can be 1.0 higher than the lowest subgrade if the lowest subgrade is edges or surface does not also apply if the lowest subgrade is corners.  In other words, even if the corners subgrade is drastically lower than the rest of the card's subgrades, the card's final grade will still only be 0.5 higher than the lowest subgrade.

The general rule is that the card's final grade can only be 0.5 higher than the lowest subgrade.  In the above Aaron Rodgers card, the final grade is 0.5 higher than the lowest subgrade.  This is because the lowest subgrade is the card's centering subgrade.  Although the aggregate difference of the other three subgrades when compared to the centering is 10.5 (the math is (9.5-5.5) + (8.5-5.5) + (9-5.5) = 10.5) which is greater than 4, that still doesn't matter because the lowest subgrade is centering.

Centering and Corners are Weighted 

More Heavily than Edges and Surface

What do all the above cards show?  They show that BGS gives more weight to a card's centering and corners subgrades than the edges and surface subgrades.

That might be supported by the fact that BGS lists the centering and corners subgrades first on the card's flip, although perhaps they were just putting the different subgrades in alphabetical order too.

From a collector's point of view, putting more weight on a card's centering and corners condition makes sense.  Those two aspects of the card are usually the most easily discernible to the naked eye, and the most influential aspect of a card's overall eye appeal.

BGS Surface Subgrade

I found another card which has a final grade more than 0.5 higher than the lowest subgrade.

Remember, the general rule is that your final grade can only be 0.5 higher than your lowest subgrade except when your lowest subgrade is surface.  When your lowest subgrade is surface, and all your other subgrades are significantly higher than the surface subgrade (such as 1.0 or more), then your final grade can be 1.0 higher than the surface subgrade.

In this dual relic card of Aaron Rodgers and Jason Campbell, you can see that the surface subgrade of 7 is the lowest subgrade on the card.  The other subgrades are all significantly higher than the surface subgrade by at least 2.5 points.  This brings the card's final score up from what would normally be a 7.5 to a 8.0.

Be sure to this previous blog post, and this one too, for more information on BGS grading.

Becket Grading Service (BGS) Surface Subgrade

In this previous post I talked about how the final BGS grade is calculated.  As I stated in that post, the general rule is that your final BGS grade can only be 0.5 higher than your lowest subgrade, unless two of your subgrades share the lowest subgrade score in which case your final BGS grade will be the lowest subgrade.

For example, a card with Centering 9.5, Corners 9.5, Edges 9.5, and Surface 9.0 will receive a final grade of 9.5.  A card with Centering 9.5, Corners 9.5, Edges 9.0, and Surface 9.0 will receive a final grade of 9.0.

This rule will work for about 90% of BGS graded cards.  Now, about that other 10%...

Sometimes, when one subgrade is drastically lower than the rest of the subgrades, the final score can be higher than 0.5 more than the lowest subgrade.  This is especially true of the surface subgrade.

The surface subgrade in BGS grading seems to be weighted the least of the four subgrades.

Take a look at the following cards which received a final grade higher than 0.5 more than the lowest subgrade.

Applying the general rule to the Aaron Rodgers card, it should have received a final grade of 7.5 because that is 0.5 higher than the lowest subgrade, but the card received a final grade of 8.0!

Applying the general rule to the Jose Abreu card, it should have received a final grade of 9.0 because that is 0.5 higher than the lowest subgrade, but the card received a final grade of 9.5!

What's going on here?!

The surface subgrade is one of those weird exceptions where if it is drastically lower than the rest of the other subgrades, the final grade can actually be 1.0 higher than the lowest (in this case the surface) subgrade.

But what about the following card?

The surface subgrade on this Tom Brady card is 8.0, and is lower than the other subgrades by 1.0.  Yet this card's final grade is still a 8.5 and not a 9.0.

What's going on here?!

As far as I can tell, there must be some hidden rule coming into play for the Tom Brady card which prevents its final grade from being a 9.0 despite the fact that all the other subgrades are at least 1.0 or higher than the surface subgrade.

My guess is that the aggregate of the difference between all the other subgrades and the surface subgrade is what determines if the final grade can actually be 0.5 higher than the surface subgrade, or get bumped up 1.0 higher than the surface subgrade.

For example, on the Aaron Rodgers card, the aggregate difference between all the other subgrades compared to the surface is:  (9-7) + (8-7) + (9-7) = 5.

On the Jose Abrue card, the aggregate difference between all the other subgrades compared to the surface is: (10-8.5) + (10-8.5) + (10-8.5) = 4.5.

But, on the Tom Brady card, the aggregate difference between all the other subgrades compared to the surface is: (9-8) + (9-8) + (9.5-8) = 3.5.

So, based on these three cards, it appears as if the aggregate difference between all the other subgrades compared to the surface must 4.5 or higher for the card's final grade to get bumped up 1.0 more than the surface subgrade rather than the usual 0.5.

It is possible that the aggregate difference between all the other subgrades compared to the surface must only be 4.0 or higher for the card's final grade to get bumped up 1.0 more than the surface subgrade rather than the usual 0.5, but since we don't have a card with those exact subgrades I cannot confirm that theory.

So, what does this all mean?

I still think the general rule that your final BGS score can only be 0.5 higher than the lowest subgrade is still the easiest way to remember how 90% (or more!) of BGS grades will work; however, I think it's good to know and keep in mind that the surface subgrade is one of those exceptions.  Remember, if the aggregate difference between all the other subgrades compared to the surface is 4.5 or more, then the card's final grade can be 1.0 higher than the surface subgrade.

Finding BGS 9.5s on COMC.com

As a buyer, one of the best benefits of COMC.com are the high quality scans that they have of the cards on the site.  They have some of the highest quality scans you'll find for cards you're about to buy.  I don't know of any other website which takes so much time and effort to supply these scans.

Usually, when you buy cards on eBay you're forced to judge the condition of the card from crappy camera phone pictures or crap scans of the card through a super-scratched up toploader.  The condition of the card is often a guessing gaming, and always a significant gamble.  Sometimes the eBay sellers don't even provide a picture or scan of the back of the card so it's impossible to know the condition of the card's back!  It's basically like trying to view a card through a dirty and scratched up window, and only looking at the front.  That is hard.  I've been burned many times because of this, having received cards which had damage and flaws which were not visible in the crap pictures and scans.

COMC tries to avoid this dilemma by providing the highest quality scans possible so you can see every print spot, see every dinged corner, and see every chipped edge.  Honestly, the only thing which I do find hard to see on COMC's scans are any gouges or scratches on the surface of the card itself, but these would be hard to see anyways on most any camera pictures or scans.

Thanks to the high quality scans on COMC, it's very possible to find raw cards for sale which are likely BGS 9.5 cards once graded.

I was lucky enough to find one when viewing Aaron Rodgers rookie cards.  Below are the actual COMC scans which I saw when viewing the card.
 

Aaron Rodgers Bowman Rookie Card

By carefully looking at all the scans of these cards, I was able to pick out which ones were in the best shape.  I carefully examined the front of the card to see which ones had the best centering.  If the centering was perfect, or at least what I would deem to be an acceptable 9.0 centering subgrade, then I checked the corners and edges.  In this case I was looking for white specks which are indicative of dings and chips.

Aaron Rodgers Bowman Rookie Card

A lot of the cards had really banged up corners and edges.  It was very easy to rule out a lot of the cards based on corners and edges alone.  In the end, I had settled on two cards which I thought to be in sufficiently good enough condition to warrant a BGS 9.5 grade.  After carefully examining the scans for print spots, dirt, or other spots which might indicate surface card damage, and then re-examining the cards' corners and edges, I bought the better of the two.  I paid $11.55 for it.  

When I received that card from COMC in my next shipment, I was pleased to see that the card was indeed in great shape.  I knew I had a BGS 9.0 at the very least and a great shot at nabbing a BGS 9.5.

Remember, to get a BGS 9.5, you have to have at least three 9.5 subgrades, and any subgrades which aren't a 9.5 must be a 9.0.  (See this old blog post for general overview of the BGS grading formula.) 

A couple months later this card was sent off to Beckett for BGS grading.  When I got it back, I was happy to see that it got graded as a BGS 9.5 Gem Mint!  All four subgrades got a grade of 9.5. 

The value of this card, having been graded a BGS 9.5, is approximately $25 to $50 on eBay.  Considering that it cost me around $15 to have it graded this wouldn't be a huge profit, if any, if I were selling it to make money but I'm not.  This is a PC card and I'm happy to just put it in my collection.  It does bring me happiness and sense of pride though, knowing that I found it raw on COMC.  This just goes to show that with a little hard work, and a careful eye, that you can find BGS 9.5 cards on COMC.

Give it a shot!

Beckett Grading Services (BGS) Authentic vs. Altered

While perusing the Blowout Cards forums I saw one interesting post in which somebody asked:

What's the lowest grade you can get on a BGS graded card?

Some people will likely say "authentic," but I believe the best answer is "1". 

First, let's look at Beckett's grading scale which is visible for all to see on their website.  It clearly shows that the lowest score you can get on a graded card is a "1". 

Poor 1

Centering: 100/0 or offcut on front or back. Heavy diamond cutting is allowed. Corners: Heavily rounded or heavily notched with noticeable layering. Edges: Destructive chipping, notching or layering. Surface: Severe print spots. Heavy creases. Severe color or focus imperfections. Heavy border discoloration. Severe stains. No original gloss. Heavy scuffing or a severe tear.

I've never seen a modern card graded that low, but in theory such a score can be obtained. 

So what is an "authentic" grade?  An authentic grade is Beckett's certification that the card contained within the slab is an authentic card made by the manufacturer, and that it's not a fake card or has been altered in any way.

How does a person usually get an authentic grade?  Usually an authentic grade occurs when you send your card to Beckett for BGS grading, and you tell them not to put a grade on the card unless it meets a certain grade of your choice, and if it doesn't then it gets the authentic grade and a blue flip. 

For example, most people will send in cards to Beckett for BGS grading and only ask for a grade if the card grades a 8.5 or higher.  This is because a grade of 8.5 is still considered near-mint, and the slab will receive a silver metallic flip in the slab.  BGS grades of 8.0 or less receive the dreaded white paper flip in the slab.  So because people are afraid to get the dreaded paper flip in the slab -- which doesn't look as good as a silver or gold flip and because the low grade reduces the card's value -- people will choose to just get an authentic grade instead.  This way, when the person sells the card later on, at least it has Beckett's certification that the card is authentic, and the buyer is unaware (unless they examine the card closely within the slab) that the card has some sort of flaws which prevented it from getting a higher grade. 

This is a card with a BGS Authentic grade.

The above picture is an example of a BGS Authentic card.  Note the blue flip, and the words "AUTHENTIC" in the upper right corner.  This card has Beckett's certification that the card is an authentic card made by Panini, from the Epix brand, that the card is not counterfeit*, and the card has not been altered.

(*Side Note: the "authentic" grade only pertains to the card and not to the patch inside the card.  Some people try to increase the value of a card when selling it by taking out bland single colored patches, and putting in fake multi-colored patches.  BGS will still give cards the authentic grade even if the card contains a fake patch.) 

It is important to note that an "authentic" grade is different from an "authentic-altered" grade (sometimes just known as "altered.")  The authentic-altered grade means that the card is authentic, but that it has been altered in some way, usually in an attempt by someone to try and get a higher BGS grade. 

This is a card with a BGS Authentic-Altered grade.

The above card is an example of an authentic-altered grade.  Note that the authentic-altered grade still receives a blue flip, but the flip says "AUTHENTIC ALTERED."  This makes it clear that while the card is an authentic card from Topps, it has been altered in some way. 

In fact, when Beckett Grading Services thinks that the card has been altered in some way, they'll even send you a little note telling you what they think is wrong.

This card received an Authentic-Altered grade because of shaved edges.

This particular Joe Montana card received the authentic-altered grade because the grader believed that the front top, and front left edges were shaved. 

So which grade is lower, an authentic grade, an authentic-altered grade or a BGS 1 grade?

Technically, I believe that the BGS 1 grade is a lower grade.  The authentic and authentic-altered grades are not actually grades per se; they're just statements by BGS that the card is authentic or altered.  A card that receives an authentic grade, could still grade out to be a BGS 6.0 (I'm just picking an arbitrary number) but because the person who submitted the card for grading put a grade minimum of 8.5 or higher, that is why it got the authentic grade.  Similarly, a card which receives an authentic-altered grade could still be in much better shape despite its supposed alterations, than a BGS 1 graded card. 

So if you ask me, I believe that a BGS 1 is the lowest grade you can get when getting a card graded.

A "1 Poor" grade is the lowest you can get from BGS or BVG.

Some people claim that some really beat up vintage cards, which are so beat up that they can't even attain a BVG 1 grade, will get authentic grades.  After perusing eBay for some examples, this claim appears to be true.  The picture below is one example. 

This particular card is in such poor condition it cannot even attain a BVG 1 Poor grade.

So in some cases, yes, an "authentic" grade can be the absolute lowest grade you can get.  But keep in mind that what "authentic" really means is just that the card is legitimate, not counterfeit, and not altered.  Some cards with authentic grades will actually be in much better condition than cards which receive BGS 1 or BVG 1 grades (such as the Brett Favre card, above). 

In conclusion, BGS 1 or BVG 1 is the absolute lowest actual grade you can get when having your card graded by BVG or BGS; however, in some instances, an authentic grade can indicate that the card is in even worse condition than a BGS/BVG 1 although not all the time.  Basically, just use your own judgment and don't automatically presume that a card with an authentic grade is in really bad condition.  It could be in very good condition or better, but it just didn't meet the minimum grade requested by the person who submitted it for grading.

BGS Grading Tip: Ink on Edge Will Result in Low Grade

I was watching a BGS mailday video by UltimateBoxBreaks.com and came across something really interesting. 

One of the cards that was sent in was a Denarius Moore 2011 Panini Prime Signatures 1/1.  Unfortunately, that card came back with a final BGS grade of 5.0!

What in the world caused it to get such a low grade?!   Well, BGS was nice enough to include a note with the card stating why its final grade was so low.  It was because there was ink on one of the edges.

Here's a screen-grab one the ink on the edge.  I've circled it in red.  It's actually a very small ink mark.  It looks like the player (or maybe the owner of the card) accidentally nicked one of the edges of the card with either a sharpie or a ball point pen.  Either way, the results is a really really, and I mean really, bad edges subgrade.

I even looked up the BGS grade online.  Here it is.

The edges got a 4!  This just goes to show how careful you have to be handling your cards, and inspecting them for flaws before you send them in.

(And as a side note, it is worth noting that the card's final grade was a whole 1.0 higher than its lowest subgrade, which is a rare exception to the general rule that you can only get 0.5 higher than your lowest subgrade.  Check out this Beckett BGS Grading blog post for more information on that.)

Now, I've already blogged about the ink stain problems on 2013 Topps Five Star Football cards.  Imagine if you sent one of those cards in for BGS grading.  You'd probably get just as low of a grade, or perhaps even a lower grade.  I've seen some 2013 Topps Five Star Football cards with big time ink stains on the corner edges -- much bigger than that little ink mark on this Denarius Moore card.  It would be such a shame if you hit a really nice card in your box of 2013 Topps Five Star Football only to find out that it had ink stains on one of the corners.  Since you would only expect that card to get a final BGS grad of about 5.0, then its value would be incredibly diminished.

UPDATE:  Since I wrote this blog post, UltimateBoxBreaks.com did another Beckett BGS Grading mailday video, and two 2013 Topps Five Star Football cards came back upgraded because of ink stained corners.   Apparently the ink stained corners were so bad that BGS didn't want to grade them.  I'm assuming that the grades the cards would have received would be even less than a 4.0. 

BGS Beckett Grading Tip: Centering

Of the four Becket Grading Service (BGS) subgrades -- centering, corners, edges, and surface -- the card's centering should be the easiest for you to evaluate on your own.  The only tool you're really need is a ruler.

It's important to keep in mind what makes for a good centering subgrade.  Beckett's own website provides guidance on this issue:

Pristine 10 centering must be: "50/50 all around on the front and 60/40 or better on the back."  

Gem Mint 9.5 centering must be: "50/50 one way, 55/45 the other way on the front, and 60/40 or better on the back."

Mint 9.0 centering must be: "55/45 both ways on the front, and 60/40 or better on the back."  

Understanding what the above language means is critical to making sure you're only submitting cards for grading which should receive a 10 or 9.5 on its centering subgrade.

The first important note to take away from the above language is that the card's front centering is way more important to obtaining a good centering subgrade than the card's back centering.  Even with 60/40 centering on the back of the card you still can get a 9.0, 9.5 or 10 subgrade on the centering subgrade depending on the card's front centering.

The second important note to take away from the above language is that to get a centering subgrade of 10, the card's front centering must be 50/50 all around on the front.  This means that the card should not be off-centered left to right or top to bottom.

The third important note to take away from the above language is that if the front of your card is off-centered both left to right and top to bottom, then you can only get as high as a 9.0 subgrade on centering (although you certainly might get lower).  A subgrade of 9.0 on centering allows for the card's front centering to be off both ways, but only by a small margin of 55/45 both ways.  However, to get a subgrade of 9.5 on centering then the card's front centering must be 50/50 one way and only 55/45 the other way.

In conclusion, if your card is off-centered on the front in both directions, meaning top/bottom and left/right, then there is no way you're going to get a 9.5 subgrade on centering.  Most likely you're going to get a subgrade of 9.0 or less on centering.  This can hurt your overall grade significantly as since the general BGS rule is that your final grade cannot be more than 0.5 higher than your lowest subgrade.  (I've covered the basics of the BGS grading formula in this previous post.)

Centering is one of the easiest subgrades for you to control and measure when you're buying cards either on eBay or COMC.  If I'm buying a card on eBay or COMC which I would like to submit for BGS grading, then I am very careful to evaluate its centering in the pictures or scans.  Since COMC uses high quality scans on their website, this makes measuring centering very easy.  I'll often enlarge the scans and use a ruler to measure the centering on the card to make sure it will garner a high subgrade.

Keep the above tips in mind when choosing cards to submit for BGS grading.  There should be no excuses for not getting a 9.5 or higher on your cards' centering subgrade if you know the BGS grading criteria and are careful to evaluate your card's centering.

Beckett Grading Service (BGS) is NOT an Average

One misconception a lot of people have with Beckett Grading Services (BGS Grading) is that the "formula" is an average.

Here's a tip:  BGS does not use an average. 

I've covered the basics of the BGS forumla in this previous blog post. 

BGS gives more weight to your lowest sub-grade(s) than your higher sub-grades.  For example, if a card has sub-grades of Centering 9.5, Corners 8.5, Edges 8.5, and Surface 9.5, the final grade will be NM/Mint+ 8.5 and not a final grade of 9.0 which is the average.

Centering 9.5
Corners 8.5
Edges 8.5
Surface 9.5

Average = 9.0
BGS Final Grade: 8.5

Remember, if two of your subgrades share the lowest subgrade score, then your final grade will be equal to that lowest subgrade.  

Beckett Grading Service Formula

I've been trying to figure out the Beckett Grading Service (BGS) "formula" in my spare time.  I've been looking at BGS graded cards on eBay and COMC.com to help narrow down the exact "formula" that BGS uses.

For the most part, it's fairly simple.  It goes like this:

• Generally, your final grade can only be 0.5 higher than your lowest subgrade. 
• Exception: If two or more of your subgrades share the lowest subgrade score, then your final grade will be equal to that lowest subgrade.

An example of the general rule would be a card with Centering 9.5, Corners 9.5, Edges 9.5, and Surface 9.0.  The final grade is 9.5.

Another example of the general rule would be a card with Centering 9.0, Corners 8.5, Edges 8.0, and Surface 9.5.  The final grade is 8.5.

An example of the exception to this general rule would be a card with Centering 9.5, Corners 8.5, Edges 8.5, and Surface 9.5.  The final grade is 8.5. 

This general rule and its single exception will probably work for about 99% of BGS graded cards.

Things get a little more complicated, however, when one subgrade is drastically lower than the rest of the subgrades (i.e. a card with Centering 9.5, Corners 9.5, Edges 9.5, and Surface 7).  In such circumstances, the final grade can sometimes be more than 0.5 higher than your lowest subgrade.  For more information about these cards, see this blog post. 

Finally, the subgrade requirement to get a BGS Pristine 10 is very stringent:

• To get a "BGS Pristine 10" final grade, you must have at least three 10 subgrades and any subgrade which isn't a 10 must be a 9.5.  (In other words, you cannot have any subgrades be a 9.0 or lower.)

For example, a card with subgrades of Centering 10, Corners 10, Edges 9.5, and Surface 10, would have a final grade of Pristine 10.

For example, a card with subgrades of Centering 9, Corners 10, Edges 10 and Surface 10, would have a final grade of Gem Mint 9.5.

Just keeping in mind the above general rule and its exception (which will work for what I estimate to be over 99% of BGS graded cards), you will be able to calculate what a card's final BGS grade should be depending on its subgrades.  This knowledge is especially useful if you are thinking about submitting your own cards to Beckett for grading.  By honestly estimating what subgrades your card will receive, you can calculate what your final grade will be based on those subgrades.