Throw out worst time?

Debates and discussions on the various race scheduling methods that can be used and their fairness and accuracy in determining the winners.
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pwd rcks
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Throw out worst time?

Post by pwd rcks » Fri Jan 16, 2009 3:17 pm

In a prerace testing with eight cars on a 4 lane Bestrack using Microwizard K-3 timer with GPRM softwart. Running Perfect N using a timed method and throwing out the worst time. We had a situation where Car A placed frist and Car B placed second. After reviewing the data we discovered Car B had won all eight races, however placed second after throwing out his slowest time. Question is what is the best way to determine overall standings? Average all times or average all times minus slowest times.



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Darin McGrew
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Re: Throw out worst time?

Post by Darin McGrew » Fri Jan 16, 2009 6:00 pm

What do you value? What characteristic do you want to reward?

My preference is to use the finish order to determine results, rather than times. But if you're going to use times, you could reward:
  • best single performance (lowest single time)
  • best consistent performance (average all times)
  • best typical performance (average times, but discard fastest/slowest times)
I don't think there is a single correct answer. It all depends upon what your group wants to reward.



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Re: Throw out worst time?

Post by gpraceman » Fri Jan 16, 2009 9:05 pm

I concur with Darin. It really depends on your definition of "fastest".

With a timed race, if you don't throw out the worst time, you are generally rewarding the more consistent cars. If you throw out the worst time, you are giving racers a chance to still win a trophy even if they have a bad run, due to something they may have had control over (racer staging, loose wheel, etc.) or maybe not (race crew staging, track conditions, etc.).


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Re: Throw out worst time?

Post by Stan Pope » Sat Jan 17, 2009 2:32 am

To stay a bit pure, if one discards the worst time, one should also discard the best time! Unfortunately, the distribution of a racers times is typically skewed rather than symmetrical, so the effect is still to bias average times lower. The more erratic the car, the greater the bias to lower the average time. The net is that the more consistent (i.e. better work quality) cars are penalized. Usually not, since those good cars tend to separate themselves sufficiently from the crowd that the abberation described does not occur.

The comment distinguishing what the youngster has control over and what the youngster has no control over is important. I am less inclined to discard runs in which the youngster has more control of the variables that if he is at the mercy of the track staff.


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pwd rcks
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Re: Throw out worst time?

Post by pwd rcks » Sat Jan 17, 2009 8:16 am

On further evaluation of data we looked at several different scenarios, the one mention originally, but we also saw that if we went with a points system that a car that had been in last placed jumped to third place. One of our biggest fear is someone (Scout or Parent) paying close attention to race finishes and wondering why if they had run every race why they went the overall winner in that Den. Looks like we are going to have to pick a method, go with it and if we are questioned explained what happened. We did keep this data in case this situation arises so we can explain the outcome. Seems there is really no best method, But some are better than others like PPN over double elimination.



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Re: Throw out worst time?

Post by gpraceman » Sat Jan 17, 2009 9:17 am

There may be parent complaints no matter how the "fastest" cars are determined. However, it can be minimized by fully explaining how the standings will be determined, before the race starts.


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Re: Throw out worst time?

Post by Stan Pope » Sat Jan 17, 2009 9:59 am

Randy,

I seem to recall that you have had "6 Sigma" training ... did they deal with distinction between an observation that was just above the mean and one that was an obvious "flyer", i.e. that was so clearly outside the norm for that variable that there is a likely error in the measurement process or the part being measured is so far out of spec that they must have measured the wrong part, like a 6mm nut in amongst the 1/4" nuts. :)


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Re: Throw out worst time?

Post by Stan Pope » Sat Jan 17, 2009 12:43 pm

pwd rcks wrote:On further evaluation of data we looked at several different scenarios, the one mention originally, but we also saw that if we went with a points system that a car that had been in last placed jumped to third place.
Why this happens is an interesting study. "Times" racing applies a weight to each run. A 3" loss more than offsets three 1/2" wins in head-to-head racing! With "points" racing, A loss by 1/4" is the same as a loss by 4" (or 4'). Depending on one's viewpoint, "Points" racing under-represents the margins of victory or "Times" racing overstates them.

A "rough and irregular" racing environment increases the opportunities for extreme variations in times. The role of luck is increased. Car design decisions can reduce the influence of "rough and irregular" tracks, but often at the expense of "top end" performance. For packs that have their own track, the racing environment is probably (should be) well known, so car design decisions can be made accordingly. For district or council races, the racing environment is unknown for most entrants.

Ultimately, though, the competition method is a "values" decision that should be made and "bought into" before racing starts. The discussion above just identifies some of the considerations that should go into the decision.
pwd rcks wrote:One of our biggest fear is someone (Scout or Parent) paying close attention to race finishes and wondering why if they had run every race why they went the overall winner in that Den.
I want the race results, who won, who was second, who finished "out of the money", to be consistent with what the Scouts and parents can see and validate for themselves. It is really difficult for spectators to validate times since they have to keep in mind too many relationships. Validating points is easier, but depends on 'who races whom" if the opponents are not well balanced. Both systems require that the spectators and racers trust that the competition details are structured intelligently and executed correctly. How you establish and maintain that trust is part of the challenge for the race director!


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Re: Throw out worst time?

Post by msurebel » Sat Nov 19, 2011 7:44 am

I'm wondering, has anyone here developed a narrative explanation of how winners are determined, that is in simple terms, so the scouts and parents will understand how winners will be determined? Being in charge of our race, I'm learning, I'm an engineer by training, but the science behind all of this could be confusing to some.

We run timed racing and I'm going to change it this year to have each age group race against only their age group, but I'm thinking I may need to provide some information on how races are determined in a written format.



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Re: Throw out worst time?

Post by Stan Pope » Sat Nov 19, 2011 8:24 pm

msurebel wrote:I'm wondering, has anyone here developed a narrative explanation of how winners are determined, that is in simple terms, so the scouts and parents will understand how winners will be determined? Being in charge of our race, I'm learning, I'm an engineer by training, but the science behind all of this could be confusing to some.

We run timed racing and I'm going to change it this year to have each age group race against only their age group, but I'm thinking I may need to provide some information on how races are determined in a written format.
Each race method has its own narrative! Embedded within each narrative are the aspects of speed which that particular race method values most. For instance, the Minimum Cummulative Time method values speed and consistency. On the other hand, Minimum Cummulative Time Dropping The Worst Run reduces the value placed on consistency.


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Re: Throw out worst time?

Post by BallBoy » Sat Nov 19, 2011 9:12 pm

msurebel wrote:I'm wondering, has anyone here developed a narrative explanation of how winners are determined, that is in simple terms, so the scouts and parents will understand how winners will be determined?
I put together a simple 2-slide PowerPoint presentation to go over before the race that explains the GPRM racing screen and has a simple explanation for how the timed scoring works with an easy-to-understand example. I have given the presentation several times and the scouts get it. In the example I give I always ask the scouts who the winner is and they always get it right.

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Re: Throw out worst time?

Post by rpcarpe » Mon Nov 21, 2011 1:11 pm

If you've already distributed your rules, it's a little late to explain the proposed racing methodology.
You will always be ahead by explaining to the race teams what happens and why.

May 2010, the timer broke and we manually ran 60+ cars just on points. We explained and everyone was happy. Until we got near the end and a Bear had not had his car run! Oops!
So we ran his car against cars that nearly made the Finals, he didn't beat those so his day was done. Again, we explained and then raced.
Good Luck!


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Re: Throw out worst time?

Post by Stan Pope » Tue Nov 22, 2011 7:30 pm

rpcarpe wrote:... we ran his car against cars that nearly made the Finals ...
Good solution!


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Re: Throw out worst time?

Post by mebetree » Sat Jan 28, 2012 8:50 am

I spent half the night last night explaining to people to not place too much stock in race wins because it was all based on time. We had 15 cars in the finals and have a four lane track (perfect N) and throw out the worst time.

Turns out, I didn't need to bother the explainations because it was my kids that were on the losing end. My older son won all 8 of his races (4 at den level, 4 in finals) but placed 2nd in his den and 3rd in the finals on time. My younger son won 7 of 8 races, only losing to his brother in the finals and he finished 1st in his den and 2nd in the finals on time.

The guy who finished 1st in the finals lost to my son in the one head to head race they had and if we were not throwing out the worst times my sons would have been 1st and 2nd because they were more consistant. He just had one blazing run and won by a few thousands of a second in combined times.

But I'm not complaining because I still think it's right to throw out the worst time in case there is a staging issue. In addition, in two races out of the 50+ heats the times for all four cars seemed to be about .2 seconds slower than normal so I think there was a glitch in the timing system or the gate drop.



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Re: Throw out worst time?

Post by resullivan » Thu Feb 02, 2012 12:44 pm

This is the problem to me with racing for who wins and that is lane selection. It should be no secret that certain lanes are faster than others. The reason a car may win all of the races but not come in first maybe just because they started in a faster lane, and possibly did not race the 1st place car when it was in the faster lane. In a four lane track you could race a faster car 3 times and win everytime just because of the lanes you are racing in. Timed races help nullify the effect of fast lanes. You really need to be comparing Car A vs Car B in the same lane. That is what the timed race does. If we have a run/jog/walk contest based on times, just because you win while you are running and I am jogging then win when you are jogging and I am walking does not mean you are faster than me. Just as run vs walk is not a fair comparison so may not lane 1 vs lane 4.



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