SQL Server, ISABOUT, weighted terms

I am trying to figure out exactly how weighted terms work in an ISABOUT query in SQL SERVER.

Here is where I currently am:

Each query returns the following rows:

QUERY 1 (weight 1): Initial ranking

SELECT * FROM CONTAINSTABLE(documentParts, title, 'ISABOUT ("e" weight (1) ) ') ORDER BY RANK DESC, [KEY]

KEY     RANK
306342  249
272619  156
221557  114

QUERY 2 (weight 0.8): Ranking increases, initial order is preserved

SELECT * FROM CONTAINSTABLE(documentParts, title, 'ISABOUT ("e" weight (0.8) ) ') ORDER BY RANK DESC, [KEY]

 KEY     RANK
 306342  321
 272619  201
 221557  146

QUERY 3 (weight 0.2): Ranking increases, initial order is preserved

SELECT * FROM CONTAINSTABLE(documentParts, title, 'ISABOUT ("e" weight (0.2) ) ') ORDER BY RANK DESC, [KEY]

 KEY    RANK
 306342 998
 272619 877
 221557 692

QUERY 4 (weight 0.17): Ranking decreases, best match is now last, inverted behavior for these terms begin at 0.17

SELECT * FROM CONTAINSTABLE(documentParts, title, 'ISABOUT ("e" weight (0.17) ) ') ORDER BY RANK DESC, [KEY]

 KEY      RANK
 272619   960
 221557   958
 306342   802

QUERY 5 (weight 0.16): Ranking increases, best match is now second

SELECT * FROM CONTAINSTABLE(documentParts, title, 'ISABOUT ("e" weight (0.17) ) ') ORDER BY RANK DESC, [KEY]

 KEY      RANK
 272619   978
 306342   935
 221557   841

QUERY 6 (weight 0.01): Ranking decreases, best match is last again

SELECT * FROM CONTAINSTABLE(documentParts, title, 'ISABOUT ("e" weight (0.01) ) ') ORDER BY RANK DESC, [KEY]

 KEY    RANK
 221557 105
 272619 77
 306342 50

Best match for weight 1 has a rank of 249 and while weight