Mineshaft determination

[KRatcliff]

The rule states.

"To decrease the potential for horsepower/index adjustments when favorable atmospheric (i.e. “mineshaft”) and/or track conditions may have contributed to extraordinary performance the NHRA has developed a system to protect the racers’ horsepower/indexes. If at the conclusion of qualifying the first competitor in the bottom half of the field is -.850 seconds or faster under the class index."

That seems pretty clear, but how do you determine the split between the bottom half reliably on an odd number of qualifiers. For example: In an 87 car qualifying field is 44 considered the first competitor in bottom half of the field? If you say yes, please show how you come to that conclusion.

This is a link to ladder for an 87 car field if that is of any help. Please note the 86 car field directly above it before you answer.

http://sacramentoraceway.com/wp-cont...1/Sptm8588.pdf