Practiscore/Match Placement Confusion

[jmac2112]

Just when I think I understand the scoring rules....  One disclaimer before I begin:  As much as I like to win, that is not what this is about.  I am genuinely puzzled by something.

 

I shot an indoor match a couple of days ago, and I can't seem to understand what Practiscore is telling me.  According to the "Overall" view, I came in ahead of all the other Production shooters.  However, when I switch to viewing just the results for Production, I find that I'm in second place.  I understand how HF is calculated, and my HF is slightly higher than the HF of the shooter whom I may or may not have beaten.  To get rid of some decimal places and simplify things a bit, my HF was 6.1 and his was 6.0. 

 

If I understand correctly, match placement is determined by dividing one's overall HF by the winner's overall HF to determine what percentage of the overall points one receives.  I'm not a great mathematician, but it seems to me that a shooter with a higher overall HF should always come out ahead of a shooter with a lower HF no matter what.  So what am I missing?

 

Here's a fact that might be relevant: The match consisted of three classifier stages and one longer stage.  The long stage was worth almost as many points as the combined points of the classifier stages, and the "other shooter" in question did significantly better than I did on that stage.  Could that fact be relevant here?

 

Thanks!

 

John

 

[Lee Cabana]

You need to factor in the fact that winning a stage works like the electoral college - the shooter who wins the stage gets all the available points for that stage, and everyone else gets a fraction of those points based on where they place in relation with the stage winner.  When you move from division winner (which is really what matters) to overall, Practiscore is recalculating who won the stage and then redistributes the fractional points.

[ChuckS]

5 minutes ago, jmac2112 said:

Just when I think I understand the scoring rules....  One disclaimer before I begin:  As much as I like to win, that is not what this is about.  I am genuinely puzzled by something.

 

I shot an indoor match a couple of days ago, and I can't seem to understand what Practiscore is telling me.  According to the "Overall" view, I came in ahead of all the other Production shooters.  However, when I switch to viewing just the results for Production, I find that I'm in second place.  I understand how HF is calculated, and my HF is slightly higher than the HF of the shooter whom I may or may not have beaten.  To get rid of some decimal places and simplify things a bit, my HF was 6.1 and his was 6.0. 

 

If I understand correctly, match placement is determined by dividing one's overall HF by the winner's overall HF to determine what percentage of the overall points one receives.  I'm not a great mathematician, but it seems to me that a shooter with a higher overall HF should always come out ahead of a shooter with a lower HF no matter what.  So what am I missing?

 

Here's a fact that might be relevant: The match consisted of three classifier stages and one longer stage.  The long stage was worth almost as many points as the combined points of the classifier stages, and the "other shooter" in question did significantly better than I did on that stage.  Could that fact be relevant here?

 

Thanks!

 

John

 

Match points are determined by the sum of the stage points, right? Stage points are determined by: (available stage points)*(Your HF/High HF). Where the variability comes in is the source of the High Hit Factor. Variations in stage winners between overall and production can account for the difference in match placement. This has been traditionally called the "flip-flop"

flipflopexample.pdf

[nasty618]

 

 

 

[HCH]

44 minutes ago, jmac2112 said:

Just when I think I understand the scoring rules....  One disclaimer before I begin:  As much as I like to win, that is not what this is about.  I am genuinely puzzled by something.

 

I shot an indoor match a couple of days ago, and I can't seem to understand what Practiscore is telling me.  According to the "Overall" view, I came in ahead of all the other Production shooters.  However, when I switch to viewing just the results for Production, I find that I'm in second place.  I understand how HF is calculated, and my HF is slightly higher than the HF of the shooter whom I may or may not have beaten.  To get rid of some decimal places and simplify things a bit, my HF was 6.1 and his was 6.0. 

 

If I understand correctly, match placement is determined by dividing one's overall HF by the winner's overall HF to determine what percentage of the overall points one receives.  I'm not a great mathematician, but it seems to me that a shooter with a higher overall HF should always come out ahead of a shooter with a lower HF no matter what.  So what am I missing?

 

Here's a fact that might be relevant: The match consisted of three classifier stages and one longer stage.  The long stage was worth almost as many points as the combined points of the classifier stages, and the "other shooter" in question did significantly better than I did on that stage.  Could that fact be relevant here?

 

Thanks!

 

John

 

 

Hit factor is what decides the number of stage points you receive on a stage. Match placement is decided by the number of match points you have, which is the sum of the stage points. 

 

Could match HF work? Most likely, and I doubt much would change. But, that’s not how the system works. 

[jmac2112]

Ah, I think I'm beginning to understand!  Within Production, the "other guy" won more points, largely because he won the stage with the most points.  Overall, however, some PCC guy probably won every stage (I'll have to go back and check).  Am I on the right track?  I can see I have more pondering to do....

 

Thanks,

 

John

[Thomas H]

1 hour ago, jmac2112 said:

If I understand correctly, match placement is determined by dividing one's overall HF by the winner's overall HF to determine what percentage of the overall points one receives.  I'm not a great mathematician, but it seems to me that a shooter with a higher overall HF should always come out ahead of a shooter with a lower HF no matter what.  So what am I missing?

 

Here's a fact that might be relevant: The match consisted of three classifier stages and one longer stage.  The long stage was worth almost as many points as the combined points of the classifier stages, and the "other shooter" in question did significantly better than I did on that stage.  Could that fact be relevant here?

 

Match placement isn't by "overall HF" because that doesn't actually exist in USPSA.  As people have said, the match points you get on a particular stage are based on your HF on that stage, compared to the high HF on that stage.   Your match placement is then based on the total of the match points you get from all stages added together.

 

In the overall results, the high HF for a particular stage is based on the highest out of everyone.  In the results that actually count (which are your Production division results), the high HF for each stage is based on the highest Production HF for that stage.  As such, the match points you get for a particular stage for division results are often different than the points you get for overall results.

 

If you could link us to the PS results for the match, we could be more specific as to how this works.

 

 

[euxx]

From the source https://blog.practiscore.com/combined-vs-division-results/

[egd5]

I love uspsa. But this is just another example of why I roll my eyes when someone says uspsa scoring is easy and simple.

[euxx]

Hit Factor scoring that uspsa is using was invented well before uspsa.

 

Also the timeplus with points scoring (widely used in 3gun) behaves the same way. I'm suspecting that's is also the main reason why UML wanted no combined results.

[RJH]

23 minutes ago, egd5 said:

I love uspsa. But this is just another example of why I roll my eyes when someone says uspsa scoring is easy and simple.

 

It takes a bit to get used to for sure.  And while it may not be the simplest form of scoring in action shooting, I think it is the most correct/fairest form, at least of all the ones i have seen

[egd5]

Oh I agree . It is correct and fair, just complicated.

[Sdlrodeo]

35 minutes ago, RJH said:

 

It takes a bit to get used to for sure.  And while it may not be the simplest form of scoring in action shooting, I think it is the most correct/fairest form, at least of all the ones i have seen

this^

[rowdyb]

And doing all the math by hand was the reason some clubs took a month to get scores out back in the day. And made errors. And made their own excel sheets and formatting. And why you had to go to each club's website to find scores. Getting scores in a timely and accurate manner was the most annoying thing about matches, to me, prior to practiscore.

 

Getting scores in 2012 was no different than 2000. And that's head shaking.... Heck, I still run into clubs who were still doing paper scoring only and hosting scores on their own website in 2019!!

Edited December 20, 2019 by rowdyb

[IVC]

The easiest way to understand this is by a simple example.

 

Consider two Production shooters in a simple match with just two stages, 100 points per stage. Shooter 1 wins stage 1 by 5% (100 to 95 points), shooter 2 wins stage 2 by 8% (100 to 92 points). The overall Production winner is based on who won by a larger margin their respective stage - shooter 2 wins the match with 195 points to 192 for shooter 1. 

 

Now consider that there was a PCC shooter who shot just stage 2 and smoked both Production shooters by having double the HF. What this does to the score in *overall* ranking is that it "kills" points on this stage for Production shooters - instead of winning 100-92 points, shooter 2 now wins by half of it, 50-46 points. While this is still the same 8% difference, the *total* of points changed drastically, from 100-92 (8 points) to 50-46 (4 points). When you add up points for Production shooters in *overall* standing, it's now 146 to 145 "win" for shooter 1. 

 

To summarize, what happens when you combine divisions is that the top combined shooter "scales" point differences between competitors in other divisions (while percentage differences are intact), which in turn can swap rankings if this scaling is uneven. For example, any stage that is particularly low-capacity unfriendly will have the totals skewed because the hi-caps will run up the HF and the differences between the lo-caps will be squashed in terms of the total points. 

 

EDIT: There is a link to Practiscore above to a blog that says the same thing... Didn't realize they had it. 

 

Edited December 24, 2019 by IVC

[egd5]

Oh yeah, that's SO simple and easy.

 

I have a much better way. Just shoot the best you can and let the computer figure it out and then accept it.

[euxx]

11 hours ago, egd5 said:

Oh yeah, that's SO simple and easy.

 

I have a much better way. Just shoot the best you can and let the computer figure it out and then accept it.

 

At some point you need more than that. There are stages where you need to know if you should push for accuracy or for speed. Also there are moments at the match when you can use additional information to decide if you should continue shooting the best you can or you should go full throttle.

 

But of course, there are computers for all of that now.

[IVC]

13 hours ago, egd5 said:

Oh yeah, that's SO simple and easy.

 

I have a much better way. Just shoot the best you can and let the computer figure it out and then accept it.

One can say the same about calculating the hit factor - "too complicated, I'll have computer figure it out." The only problem is that then you don't know whether to wait on that swinger's second pass or take a possible mike, whether to engage a disappearing target, or how much extra time you can spend on difficult shots to get A vs. C. 

 

If you don't want to know how it works, here is a simple rule of thumb. The ranking cannot flip if one shooter is better on all stages than the other. The ranking is much more likely to flip if you shoot lower scoring division (Production, Revolver, SS) and if your performance varies from stage to stage so that your ranking in the division takes wild swings. For anything more, you'll have to understand the math. 

[shred]

"Shoot good points as fast as you can" is rarely a bad strategy.

 

But knowing how hit factor works is useful, even if you don't calculate it exactly.  At club matches, don't let the scorekeeper auto-accept for you, check your HF and learn what types of stages and shooting get you what.

 

I overheard Stoeger telling Vogel while walking through a stage at Nationals something like "It'll hurt your heart, but you'll have to take some Charlies on this one".