I know this is nitpicking, but the last review of PGR4 came from gamerevolution, and it was deemed a 50% but the grade GameRev gave PGR4 was a C which in a grading system as seen here...

* A = (90 to 100)
* B = (80-89)
* C = (70-79)
* D = (60-69)
* F = (0-68)

should equate to a 70 at the least, but more likely a 75 as that's the median. I know this sounds anal, but that one score brings down the ranking of the game. Just looking out for Meta's credibility

Well, welcome to the site, Mass Debater. Seeing as your are new it is easy to see how based on an elementary scoring system, like the one you displayed, a C would equal around a 75.

MC has a different grade conversion scale. Go here to see the full questions/answers about MC. Scroll towards the middle and you will see the scale. But it goes something like this:

Letter Grades
Their Grade and what it Converts To:

A or A+ = 100
A- = 91
B+ = 83
B = 75
B- = 67
C+ = 58
C = 50
C- = 42
D+ = 33
D = 25
D- = 16
F+ = 8
F or F- = 0

That's why the C score was scaled as a 50. Anyways, I hope that helps and please do take a look at the link I posted as it can better answer any of your other questions.