Maximum time differential

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Gib Lewis
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Joined: Thu Sep 22, 2005 2:52 pm
Location: Breckenridge, CO

Maximum time differential

Post by Gib Lewis » Wed Dec 06, 2006 8:03 pm

I was recently able to attend a world class alpine snowboard slalom race. As many of us noticed in the Parallel Giant Slalom run in the last Winter Olympics, they race head-to-head much like skateboard slalom.

Snowboard racing rules are a bit different than those used in skateboard racing. One rule that they use might be worthy of consideration for a change in the way we do things in skateboard racing.

Snowboard racing uses something called a Maximum Time Differential. Currently, skateboard racing uses a DQ Penalty (typically 1.5 sec or so). With a DQ Penalty, skateboarders should be incouraged to pull out of the course if they are loosing by too much so that their time disadvantage is limited to only that assigned by the penality. With a Maximum Time Differential, racers can continue to make the course while allowing them to only loose by the assigned time differential. It seems better to encourage people to race rather than pull out. Further it seems bad to penalize racers for not having the sense to pull out.

Under the DQ Penalty, there have been a lot of situations where a second race run has been set up where the time advantage is greater than the DQ penality. If the person with the advantage would not even run (fall off the start ramp?) and win the race, why run the race?
Last edited by Gib Lewis on Thu Dec 07, 2006 2:11 am, edited 2 times in total.

Claude Regnier
Claude Regnier
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Your Right!

Post by Claude Regnier » Wed Dec 06, 2006 9:36 pm

Gib that is a good point. It is probably no to late to add it into the Slalom race rules debate.

This happened to me a couple of years ago when the other race pulled out and DQ. Was it on purpose or not? We just don't know.

If I did this right this is the direct link!

Many Happy Pumps!

John Gilmour
Team Roe Racing
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The time penalty

Post by John Gilmour » Thu Jan 10, 2008 5:43 am

The time penalty is arbitrary.

And so....

If a racer is intelligent to limit his losses by taking the DQ that is fine. He still loses.

Lets say a racer apexes a turn in front of flat or even slight uphill section and slides out completely losing his speed... more than 1.5 seconds could mount.
It is then in the racers best interest to DQ himself rather than possibly plow very close to the DQ limit to struggle to catch up ad perhaps make it even worse.

I think 1.5 seconds over a typical course...well it's not much of a threat to the faster racer. And if the faster racer is paying attention and sees the other racer pull out...he can coast to the finish to conserve energy anyhow. The faster racer still gets a 1.5 second advantage into the next run.

Realistically as the racers skill level of everyone gets closer.... we won't see many skaters taking advantage of this strategy except for novices...who need all the help they can get against a mature racing field.

The real problem that could be presented is if one course was more than 1.5 seconds faster than the other. In this instance ..... if you were in the slow course first... You should DQ yourself immediately (or even more evil, trick your opponent into going full bore for the whole course while you coast and save energy) and then you would have a distinct advantage going into the faster lane. This would always give an unnatural advantage to the racer who drew the slower land for the first run.

In races where one lane never produces a winner in the quarter finals.... you might be suspicious about one lane being faster than another.

In this case.. the promoter should have to raise the DQ level to a much higher level to discourage this strategy. Even so... depending on which course you DQ on... it is still not even. Once course a DQ means a lot worse than the other in the case of uneven courses. DQ in the uneven fast course.....and there is no way you could ever make it up even against a much slower competitor in a 32 bracket.. that distorts the bracket and is bad.

Had I been racing in one race held at one world championship in California. (won by Tay Hunt).. if I looked at the times on each lane... I might have tried such a strategy... if I was given the slower lane first and thought the course differential was greater than the DQ penalty (and saving energy in the semi finals was a paramount advantage). It pays to pay attention..and if doing such a thing causes outrage... well then it makes promoters pay even more attention to making each course similar and fair. It isn't fair just because both racers race the both courses still one of the racers can have an advantage depending on who races which lane first.
One good turn deserves another
john gilmour

Gib Lewis
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Hmm, more clarity...

Post by Gib Lewis » Fri Jan 18, 2008 12:00 am

It seems that the DQ Penalty doesn't serve our racing community too well under some circumstances. I hope the following helps clarify this point.

Object of head to head racing: best combined time from each of 2 courses

Under the DQ penalty based rule system, if a racer DQ's (doesn't complete a course
run), the DQ'ed racer is assigned a time equal to the opponents time plus the DQ
penalty. The DQ penalty can be assigned by the organizer for each race. It is
often set at 1.5 sec--a value that provides a substantial lead for the non-DQ

DQ time penalty = 1.5 sec
Racer A vs Racer B

1st Rule Test Case: Both courses identical
1st Race:
Racer A wins by 1.501 sec after cone penalty is assigned.
2nd Race:
Since this is a WELL ORGANIZED race all times are known by everyone.
Racer A knows he beat Racer B by more than the DQ penalty
Racer A rolls off start ramp and runs out of course
Roll out of course could be intentional or unintentional
Racer B has the run of his life beating Racer A's previous time by 2.5 sec
Even though Racer A was not running beside him to incourage a better run.
Racer A wins because he beat racer B by more than the DQ penalty in 1st run.
Organizer could have saved overall event time by choosing to not run 2nd race.
Enforcing a rule against an intentional DQ is probably not practical.

2nd Rule Test Case: Left course faster than right by 2 sec.
Racer A in left course, Racer B in right.
1st Race:
Racer A wins by 2 sec in left course.
2nd Race:
Racer A pulls out of right course after 3 cones
Racer B has a good run, beating racer A's left course time by 0.75 sec
Racer A wins because he was put on faster course for first run.

DQ Penalty Rule Assessment.
Hiding times from racers helps hide this rule deficiency. I regard hiding times
from racers as a sign of a POORLY RUN race.

In this rule system, a maximum time differential is in effect even if both racers
sucessfully get a time. If one racer dominates a race, the winning margin is
decreased to help even things out. If one racer doesn't complete the course, his
opponent is given a time advantage equal to the Maximum Time Differential. The
Maximum Time Differential is set by the race organizer.

Max Time Differential = 0.75 sec

1st Rule Test Case: Both courses identical
1st Race:
Racer A wins by 1.501 sec after cone penalty is assigned.
Victory margin is reduced to 0.75 sec Maximum Time Differential.
2nd Race:
Racer B wins by 0.76 sec after cone penalty.
Racer B wins based on combined margin of 0.01 sec (possible upset).
Both runs were necessary (both racers needed to be on their game for each run).

2nd Rule Test Case: Left course faster than right by 2 sec.
1st Race:
Racer A wins in left course by 2.1 sec after cone penalty
Victory margin reduced to Maximum Time Differential of 0.75 sec
2nd Race:
Racer B wins in left course by 1.9 sec after cone penalty
Victory margin reduced to Maximum Time Differential of 0.75 sec
Both runs were necessary.
Maximum Time Differential combined time results in a dead heat.
Need to examine single run times to determine winner (Racer A in this case).

Maximum Time Differential Rule Assessment.
Tends to even out large margin victories making things more competitive.
Removes incentive for racer to intentionally DQ his way to victory.
Makes it necessary to take all runs more seriously.
Effects of widespread racer result dissimination less important.
Easier to have a well run race.

Overall Rule Set Comparison:
When compared to the DQ Penalty rule set, the Maximum Time Differential approach
more encourges racers to put in a best effort on each run and make mismatched
races more meaningful.

Pat Chewning
Pat C.
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Artificially constructing times from a DQ

Post by Pat Chewning » Fri Jan 18, 2008 1:40 am


Excellent points and analysis.

This highlights the basic flaw in any system where we try to construct a time for a racer who has DQ'd the course. It is fraught with problems and scenarios where it just doesn't make sense.

This is why I think a DQ should be a "real" DQ -- i.e. a 999.999 second run. No matter how hard we try, artificially constructing a time for a racer who has DQ'd is a flawed concept. It is like giving a goal when the ball hasn't passed between the goal posts.

In our 2008 rules update, the racers voted for the 1.5 second DQ penalty. There was no proposal to implement a "maximum time differential" limit. That is why the ISSA rules are the way they are.

The "maximum time differential" doesn't fix the problem. (See your example where racer A gets a better combined time over two runs, yet loses to racer B).

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