Thursday, April 24, 2014

Supercollecting Science: Let's Crunch Some Numbers

Since I started keeping a running count of all my Griffeys, I now have a great source of historical data to play around with and extrapolate information from.  This post is a six-month progress report on the acquisition of Griffeys and the general growth of the collection based on the numerical data gleaned from changes in the Griffey count.  It’s all very exciting in a math-y sorta way.

First, let’s talk about where this thing is meant to go.  As you can see (at the time of this post), the total Griffey count is at 7,458 total cards with a unique Griffey count of 2,949.  This gives us a current duplicate ratio of 2.529, a 6-month decrease of 0.061.  This number is an indicator of collecting efficiency whether it is purchases or trades, so I try to keep it low.  A dupe ratio of 1 would mean zero duplicates and perfect collecting efficiency.  My goal is to have a ratio that is always shrinking, but I feel like it’s probably just going to hover around the 2.5 mark unless I do something drastic.

Now I could, if all I wanted was a lower dupe ratio, sell 823 duplicates and instantly achieve an overall dupe ratio of 2.25, but where’s the fun in that?  I could also acquire 641 new unique Griffeys with zero duplicates (dupe ratio at an even 1.00).  That would get my “slash line” to 8099/3600/2.250.  Doesn’t that sound better?

The Beast has changed the game

Let’s talk about these numbers in the context of the newest, biggest, baddest addition to this blog: a canonical list of every unique Griffey card in my collection that I call The Beast.  I put The Beast together for a few reasons, but the one most applicable here is that it keeps me from buying duplicates.  I’m guilty many times over of perusing COMC or card shows and picking out a load of cheap cards I don’t recognize only to find those same cards staring back at me when I go to file them in the binders.  How embarrassing.  The plan is that implementation of the Beast as a reference will lead to a lower dupe ratio.

When we look at just the Griffeys added over the last six months, the current trends become clear.  The total Griffey growth from 10/24/2013 to 4/24/2014 is 1,140 total cards, 506 of which were new unique Griffeys.  While my overall dupe ratio is hovering right around 2.529, the dupe ratio for new acquisitions in the last six months was a wonderfully low 2.253.  This means I'm collecting at a higher efficiency.  I’m also averaging a daily increase of 6.33 Griffeys, 2.81 of which are new, unique additions.  You read that right - just under three new Griffeys a day.

Going forward I expect to see the overall growth level off as the number of unique cards continues to grow.  The result of these trends in concert will be a smaller dupe ratio.  This is thanks in part to The Beast being fully operational.

So yeah. I really just wanted to get all this down in black and white before the true effects of The Beast are felt. Hopefully this post doesn't scare folks away from sending me duplicates in trade.  I still love me some dupes.


  1. Great post. My love for numbers and statistics has always been a big reason I collect. This is great data. That's insane that you have nearly 3,000 unique Griffeys... Awesome.

  2. Yeah, but what's your BABIP? Also, are these numbers adjusted to your homefield? You're at a low altitude, so your averages might be deflated due to the thick air. I would also like to check your binders for PEG's (performance enhancing Griffeys) that may nullify the more bloated numbers.

  3. Just Googled BABIP. Turns out it's really a thing.