PSA (OC) - What's the Point?

[mferronibc]

I am fairly new to the boards so I apologize if this is a topic that's been discussed before. I am just getting back in to collecting vintage cards - trying to build a collection for my newborn son that will give us a hobby together when he is older. I am trying to walk the exciting (and sometimes manic) balance between finding cards with a decent PSA and favorable POP report so at least I can feel good about them retaining value, if not gaining, as some degree of an investment for him - better than the stupid savings bonds people bought for me when I was born - and cards that I find visually appealing of classic HOFers so hopefully he'll develop an appreciation of the game's heroes and legends.

That lead me to researching alot on the PSA auction results site and I am thoroughly confused about the (OC) designation. It seems to drop the going price for any card by 2 full points. For example, a 1960 Mantle All Star PSA 9 (OC) just sold on Ebay last night for $345. (It was actually a really nice looking card with the all around white border you could barely tell it was so off centered but this seems like the exception). A straight up PSA 9 of the same card goes for like $1300-1350, an 8 goes for $400-600 and a 7 goes for $275-300.

I guess my question is why isn't this card just a 7?? Does it really mean anything if it is technically a 9 with an * that reduces it's price and appeal? I mean isn't centering a fundamental criteria for grading cards in the first place? If so, why does this qualifier even exist? For me, centering provides way more appeal than sharp corners. For my money I'd rather have a nicely centered 7 (or even a 5 for that matter) with 1-2 dull corners than an off centered 9. After all, isn't symmetry a fundamental biologic (and well-studied psychological) criteria for beauty and attraction?!

I'm sure it has to do something with that corners, etc show the card's true wear over time and off-centering is thought to be just an error of processing - i.e. not the fault of the person who owned it in terms of keeping it preserved. But does it matter when we're talking about overall appeal?

I'm curious to hear from people who often buy (OC) cards and what the motivation is. Is it thought to be more marketable later on as a "PSA 9"? Maybe bragging rights to your friends - "Just got a sweet PSA 9 Mantle...cough cough OC for dirt cheap..."?