I need help understanding the math in bracket racing. The following are the actual times from a 1/8th mile bracket race ticket. The question is which vette won the race and why? I know who the ticket says is the winner, but I was surprised.

Vette A: Dial-in=9.90 RT=.024 I1=2.552 ET=10.403 MPH=71.642

Vette B: Dial-in=9.40 RT=.063 I1=2.724 ET=9.890 MPH=75.806

Nobody but the two old guys racing could claim it was an exciting race, so try to be kind when you answer. At least give credit for the reaction times.

:steering:

 

The easiest way to figure out who won a bracket race is by the "Package". The Package is the total amount of error.

Error is broken up into two pieces. 1) Reaction time error 2) Dial-in error

The first thing you look at is, did somebody redlight, and if both redlighted, the 1st one that went red loses the race. Neither of the two cars in your example went red so the race was on.

The next thing you look at is did either of the vehicles break out... if both broke out, the one that broke out by the least amount wins the race. Neither of the two cars in your example broke out, so we know we have a clean race based upon who made it to the finish line 1st.

Vette A: Had a very nice .024 reaction time and ran a poor .503 off its dial in for a total error of .527

Vette B: Also had a respectable .063 reaction time and ran an also poor .490 off its dial in for a total of .553 error.

Thus we have .527 error vs .553 error, telling us that Vette A took the win light by just a few feet based upon the trap speeds you were running at the 1/8th.

Hope you were Vette A :)

cheers,
Beach Bum


[Modified by Beach Bum, 7:18 PM 6/22/2003]

 

Thanks Beach Bum. I can understand the results now.

I had thought the reaction time was part of the ET and couldn't figure how Vette A could have crossed the finish line first. Having assumed the reaction time was already included in the ET, it appeared that Vette B crossed the finish 10.390 seconds after Vette A's green light and thus should have earned the win with a margin of .013 seconds. As you explained, the quicker reaction time for Vette A contributed to his win.

 

Yes, that is a common mistake of new racers to believe that reaction time is part of their actual et.... your et does not start until after the reaction time, which is simply how much time it took you to get out of your rollout and break the start beam, which is typically 1 to 12" depending on how deep you stage.

I would guess your ticket shows a "MOV" (margin of victory) as: .026

have fun racing.

Beach

 

And quite a few, NOT so new racers, too.

Beach,
That was a very eloquent explaination. It answered questions (red light and break out) not even asked. Superb!

RACE ON!!!
1984 Crossfire
Member NHRA

 

Oh...the picture becomes clearer, now that I know the acronym... :cheers: :thumbs:

 

Beach nice job:D