Getting discard profile to work for high point scoring system

One of my sail clubs uses a simple high point scoring (score = s-p+1) for its weekly races with spotty attendance (hence the use of a high point system to factor in fleet size in the results). They asked me to add a typical discard profile (0,0,0,0,1,1,1,1,2,2,2,2) to the scoring.

Sailwave picks up the right worst scores (the lowest ones) then takes them out of the total, thus reducing the total and potentially the ranking.

For instance top racers loose lot of points since their worst are at the top of the rankings, while the laggards loose much less.

Discarding a DNC score (with a score of 0 point) does not change the total and defeat the purpose of factoring attendance in the scoring. The same holds for other such scores - OCS for example (score of 0) does not change the total and essentially behaves like a non-discardable score. And so on.

Imagine 2 top racers - one with his worst score being for a great finish, with the other one having an OCS - everything else being equal. Apply the discard profile as is and the one with the OCS pulls ahead - obviously not the right thing.

Indeed taking scores out is the wrong way to go for high-point systems. Discarding should “increase” the total, not reduce it (the mirror behaving of low point system where taking out scores lowers totals and improves ranking).

At the moment, I run Sailwave to spot the worst scores, remove the discard profile and enter manually a score of “s” to these worst scores - time consuming and unreliable for sure.

Anybody knows a way to make discard profiles for high score systems work properly in Sailwave?

Thanks

Mario

I think you're mixing up two issues: (1) can Sailwave do "XYZ" scoring
system and (2) what scoring system would be fair for us to use.

1. A "simple high point" system discards the smallest scores. A score of
zero for DNC is certainly the smallest and Sailwave properly discards
it. Since the highest score wins, discarding the smallest scores allows
for the biggest possible score at the end, which is the goal of each
boat under a "simple high point" system. I don't see any problem with
Sailwave or its scoring options. I don't think it is terribly fair but I
believe it is widely used.

2. On the other hand, it sounds like you don't want a "simple high
point" system and want to ignore DNCs (and possibly other scores as
well). Some scoring systems take your total score and divide by the
number or races that you sailed in. These are sometimes referred to as
"average score" or "batting average" systems (the latter being a term
from baseball). In essence, these systems give you an "average score" -
the largest average score wins. Another approach is to take the points
you earned and divide by the number of points you would have gotten if
you'd won every race that you sailed in. Such systems are sometimes
referred to as "efficiency" or "percentile" or "percent of perfection"
systems - the highest percentile wins. Both of these types of systems
have obvious problems - without some additional conditions the boat that
wins the first race should never come out again as it already has a
perfect percentage. This is typically handled by requiring a minimum
number of races to qualify for series trophies (often 70% or 80% of the
races held).

I think one might be able to justify ignoring DNCs (and maybe DNSs) in
one of the average or percentage systems. However, ignoring an OCS or a
DSQ would be inappropriate except as part of a discard system (as
opposed to an average or percentage system).

Sailwave cannot score an average or percent of perfection type of
system. It can score individual races by implementing the appropriate
formula but it cannot do the series averaging and dividing at the end
(at least not that I'm aware of and I looked into this a low a few years
back).

My club developed a system we call the "Sunset Scoring" system (after
the name of the race - the Sunset Series) which attempts to address the
shortcomings of other high point systems. Plus, Sailwave can score it
and several clubs are using it (we don't because while it can do fleet
scoring it cannot do division scoring). We calculate scores based on
fleet size - basically your percentile ranking in the fleet that sailed
in that race. We count all races but allow throwouts (3 discards for 20
races but you could certainly increase that number). Since you always
get to throw out your worst scores every boat has an incentive to keep
coming out and improving their series score by doing better than their
best throwout. Bias based on class size is eliminated (see below). We've
used it for over 10 years now and it is well accepted.

Class-Size Bias. The Low Point System favors boats that sail in races
with fewer boats (since it is easier to get a lower score in a small
fleet) while a simple high point system favors boats that sail in races
with more boats (since it is easier to get a larger score in a large
fleet). An important motivation for the Sunset Scoring system was
eliminating (or reducing as much as possible) any bias based on class
size. A middle boat gets the same number of points regardless of class size.

If you are interested I can go into more detail or there are a bunch of
prior messages in the group dealing with the relevant issues and
alternative systems.

I think you want to decide what your goals are before you decide on a
system. And, kind of obviously, you need to decide on the specifics of a
system before trying to implement it in Sailwave.

Art

···

On 9/1/2015 7:30 PM, mario.poirier@yahoo.ca [sailwave] wrote:

One of my sail clubs uses a simple high point scoring (score = s-p+1)
for its weekly races with spotty attendance (hence the use of a high
point system to factor in fleet size in the results). They asked me
to add a typical discard profile (0,0,0,0,1,1,1,1,2,2,2,2) to the
scoring.

Sailwave picks up the right worst scores (the lowest ones) then takes
them out of the total, thus reducing the total and potentially the
ranking.

For instance top racers loose lot of points since their worst are at
the top of the rankings, while the laggards loose much less.

Discarding a DNC score (with a score of 0 point) does not change the
total and defeat the purpose of factoring attendance in the scoring.
The same holds for other such scores - OCS for example (score of 0)
does not change the total and essentially behaves like a
non-discardable score. And so on.

Imagine 2 top racers - one with his worst score being for a great
finish, with the other one having an OCS - everything else being
equal. Apply the discard profile as is and the one with the OCS pulls
ahead - obviously not the right thing.

Indeed taking scores out is the wrong way to go for high-point
systems. Discarding should "increase" the total, not reduce it (the
mirror behaving of low point system where taking out scores lowers
totals and improves ranking).

At the moment, I run Sailwave to spot the worst scores, remove the
discard profile and enter manually a score of "s" to these worst
scores - time consuming and unreliable for sure.

Anybody knows a way to make discard profiles for high score systems
work properly in Sailwave?

Thanks

Mario

—In sailwave@yahoogroups.com, <mario.poirier@…> wrote :

Anybody knows a way to make discard profiles for high score systems work properly in Sailwave?

It is working properly really. Its intrinsic to any discard system - or, to put it another way - best N races only count system - that a competitor who has more than N good races gains no scoring benefit from the extra good results. Whether this is right and wrong for your club results only your club members can decide. But if you want every good result to count then you can’t have discards.

Art frames the pros and cons of high point, low point and betwixt and between very well.

The only thing I’d add is that before doing making changes to scoring systems always rescore a few old series with your proposed new system and see how much difference it makes. My experience is that much of the time there will be no major differences, and whilst I’ve seen minor ones, place swaps and the like, it was never obvious to me which set was fairer or more representative, so in the end we stuck with standard low point. There are some alternates that seemed to me significantly more unfair (Ostrobogolous or O league was an example), but I’ve never come across one that seemed markedly better in practice.

I heartily endorse going back and redoing old races. The last time we
switched scoring systems for our summer-long series we re-scored the
prior 3 years worth, just to make sure there weren't going to be any
unexpected issues (there were issues, but all expected because of our
re-scoring).

By the way, there are probably close to ten different high point systems
in common usage around the world. All have pros and cons and I think all
are worth investigating. Don't let my preference influence your decision.

Art

···

On 9/2/2015 2:34 AM, yho@devboats.co.uk [sailwave] wrote:

---In sailwave@yahoogroups.com, <mario.poirier@...> wrote :

Anybody knows a way to make discard profiles for high score systems
work properly in Sailwave?

It is working properly really. Its intrinsic to any discard system -
or, to put it another way - best N races only count system - that a
competitor who has more than N good races gains no scoring benefit
from the extra good results. Whether this is right and wrong for your
club results only your club members can decide. But if you want every
good result to count then you can't have discards.

Art frames the pros and cons of high point, low point and betwixt and
between very well.

The only thing I'd add is that before doing making changes to scoring
systems always rescore a few old series with your proposed new system
and see how much difference it makes. My experience is that much of
the time there will be no major differences, and whilst I've seen
minor ones, place swaps and the like, it was never obvious to me
which set was fairer or more representative, so in the end we stuck
with standard low point. There are some alternates that seemed to me
significantly more unfair (Ostrobogolous or O league was an example),
but I've never come across one that seemed markedly better in
practice.

Hello Mario,

Sailwave works fine witch high point scoring systems. I
don’t know, whether I understood your problem.

I think it is allways o.k. that “DNC” is scored
with 0 points and that “DNC” is discardable. The last competitor of
every race gets at least 1 point. Your problem is, that a boat with “DSQ”
or “OCS” will not be punished, because this results will also be
discarded - this are the worst results for those boats. You should edit/change
in your scoring system the setting of the codes “DSQ” and
“OCS” from “discardable” to “do not discard”, and your problem is solved.

For our wednesday evening races at Wilhelmshavener Segelclub
we defined for “DNF” a value of 1 point, to promote those, who start in
a race, against those, who didn’t come.

Christof