Barrier Position Penalties
Lots has been written about barrier positions and their influence on different methodolgies. This table (applied generally and not specifically) is about as good as I have come across for making allowances for whatever system you are using.
BARRIER WEIGHT (kgs) LENGTHS 1 0 0 2 .1 .07 3 .21 .14 4 .32 .21 5 .43 .28 6 .53 .35 7 .64 .42 8 .75 .5 9 .85 .57 10 .96 .64 11 1.07 .71 12 1.17 .78 13 1.28 .85 14 1.39 .92 15 1.49 1.00 16 1.6 1.07 17 1.71 1.14 18 1.82 1.21 19 1.92 1.25 20 2.03 1.35