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

[Cotten]

I think 45 is the top of the bottom half, because he comes up and runs number 2 on the ladder.

I have no documentation to support this theory, however.

[GTX JOHN]

Mike is nearly always correct in my experience.

However, I think 44 is first on on bottom 1/2 of the ladder.

I will show my work (Like in 3rd Grade) ---

87 divided by 2 = 43 1/2 (arithmetic middle of Field)

44 first on bottom 1/2 of field.


Of Course I am generally Wrong! You can verify
that with my X-Wife!

[HawkBrosMav]

Originally Posted by GTX JOHN

Mike is nearly always correct in my experience.

However, I think 44 is first on on bottom 1/2 of the ladder.

I will show my work (Like in 3rd Grade) ---

87 divided by 2 = 43 1/2 (arithmetic middle of Field)

44 first on bottom 1/2 of field.


Of Course I am generally Wrong! You can verify
that with my X-Wife!

I'll chime in with a simple way to figure it out... using your math John.

87 car divided by 2 = 43.5 like you stated

this means there will be 44 cars returning for 2nd round. This would make the 45 car the 1st car on the bottom half of the field...

We split the field in "half" every round so if all the top qualifiers won the entire TOP half of the field would return for round 2 and the highest qualified car not returning would be the FIRST car on the bottom half of the field...

Brad

[Jeff Stout]

Round up to next even number. Divide by 2 and next number is top of bottom half. 850 under or greater is mineshaft.

[jmantle]

Originally Posted by Jeff Stout

Round up to next even number. Divide by 2 and next number is top of bottom half. 850 under or greater is mineshaft.

Wouldn't make more sense to look at the actual weather conditions rather than how many sandbaggers show up? Just a thought.

Jim Mantle V/SA 6632

[Pete Lanciers]

Originally Posted by GTX JOHN

Of Course I am generally Wrong! You can verify
that with my X-Wife!

LMMFAO! thanks John!

[countrypuppy4865]

Rule of thumb is the first car on the bottom half will run #1 or #2 qualifier if it’s an odd number. If that car isn’t -.85 then it’s not mineshaft.

[KRatcliff]

Originally Posted by Cotten

I think 45 is the top of the bottom half, because he comes up and runs number 2 on the ladder.

I have no documentation to support this theory, however.

You are correct and the ladder would be the documentation. Drew gave a simple explanation that basically the ladder is identifying the #1 qualifier of the bottom half of the ladder. Super simple with an even number of cars, because the #1 overall qualifier runs the #1 qualifier of the bottom half of the ladder.

For an odd number of cars, the #1 overall qualifier gets a bye run and the #2 overall qualifier runs the #1 qualifier of the bottom half of the ladder. By proxy, the #2 qualifier will identify the top qualifier of the bottom half of the ladder.

Jeff gave a simple mathematical example how to determine this. Using an 87 car qualifying sheet you would round up the the next number of 88 then divide by 2 = 44 then you add 1 to that number to get 45. In my example of an 87 car field for mineshaft calculations the number 45 qualifier would make the determination.

This can be verified with this link. http://sacramentoraceway.com/wp-cont...1/Sptm8588.pdf

Ken mentioned that someone said it was number 43 at VMP, but was that a typo? Did you mean 45? You can verify on the ladder that I linked that number 43 would fall into the top half because they were paired with number 86 for the first round.

It doesn't appear that the VMP race on October 3rd would be a mineshaft race since number 45 was only -.845

[Whalen3186]

Originally Posted by KRatcliff

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.

Error-proof way to remember it, look at the fastest qualifier that is on the bottom side of the first round pairings. This is the opp of the #1 OR #2 qualifier if an odd number of cars.

For 87 and 88 car ladders the first qualifier in the bottom half is #45.