rAvg verse BOS (beeradvocate overall score)

I tried to search this before posting to make sure it hasnt already been pointed out. I hope this isn't redundant. I also realize this is probably a mute point after the site redesign but I figured I would just throw this out for consideration.

For this example, lets use Captain Lawrence brewery and select a few random beers:
Captain's Reserve Imperial IPA
Golden Delicious
Hops N' Roses
Mother Barrel Select

The BA overall score purpose is by definition: "Its purpose is to help make some sense out of the rAvg (1-5 based review average) and provide consumers with a quick reference when comparing one beer or place to another."

Why is it that the BA overall score does not list the beers in the same numerical order as the rated average? For example, if you take just the rAvg into consideration, the beers mentioned above appear in this order from highest rated to lowest:

1. Mother Barrel Select 4.12
2. Captain's Reserve Imperial IPA 4.1
3. Hops N' Roses 4.07
4. Golden Delicious 3.93

However, based on the BOS those same beers are listed in this order from highest to lowest:
1. Captain's Reserve Imperial IPA 91
2 &3. Golden Delicious and Hops N' Roses tied at 88
4. Mother Barrel Select 87

I guess the point I am trying to make is that if a person is given the choice to only purchase 1 or 2 beers from a brewery on their budget, chances are they would want to go for the one rated highest (assuming all other things constant.) However, depending on which rating/score the person looks at would yield 2 different sets of results.

I assume that the discrepancy has something to do with the number of reviews for each beer being taken into consideration. However in the big picture, does it really make sense for a beer to get a lower number "overall" because fewer people have reviewed it? I think my random example of 4 happenstance selections is quite unique considering mother barrel appears #1 on one list and last on the other.