Standards Based Grading (SBG) vs. Another Assessment

In my district, students take an assessment by Discovery Education.  Students take "Benchmark" Assessments four times during the school year.  The assessment gives feedback about a student's performance and labels them as Level 1-4.  Levels 3 and 4 indicate meeting or exceeding standards.  Although this is just one test that students took on one particular day, I was curious to see how the results of our first Benchmark test compared to my first quarter SBG grades.

I compared them equating an "A" or "B" as Level 3-4, "C" as Level 2, and "D" or "F" as Level 1.  Here is the comparison:

I was surprised by how much the two forms of assessment have in common.  

One of the reasons that I decided to try SBG this year was that I knew it was confusing to parents to see their child do poorly on an assessment such as the Discovery Education Test or our state test (ISAT) only to be receiving a "B" in my class.  Artificially inflated grades due to homework completion was the reason for the discrepancy.  I think my new way of grading gives parents more accurate feedback on how their child is doing related to the 8th grade standards.