Fair points value vs distance to target?

[InTheBlack]

I'm one of the people tasked with creating courses of fire for this season at the Fish & Game where we shoot once a month in an informal match.  We allow whatever equipment someone wants to use (nobody is into the race guns/holsters, though) only divided into 9mm/.38 vs larger calibres.

We need to cater to all skill levels.

I was thinking that it would be nice to create stages where the shooter would fire a specific number of shots, but could choose the distance to suit his own level of skill.  So the long range targets need to be worth more points.

My question is, what's a fair way of assigning the points value between, say, 7, 15, and 25 yards-- One, Two, Four?

I'm also interested in opinions on what amount of time is 'par' at various ranges to "normalize" their difficulty.  If I need 1/2 sec/shot at 7 yards, is that better than you taking 1 sec/shot at 25 yards?

Those of you who keep track of your practice times & scores have solid data on these questions.

[benos]

ITB,

Good question with interesting potential. What will you use for targets?

I don't have any solid data, but I do have a general vibe. It seems as if the shot "difficulty factor" increases expotentially with distance. To the tune of about the power of 3 or 4. And that is not considering time. That is to say it is maybe 3 or 4 times as hard to hit the same size target at 50 yds as it is at 25. And, the target size must be considered. It may not be much more difficult to hit a garage door at 50 than at 25, but it is certainly 3 or 4 times harder to hit an 8" plate at those distances. Likewise shooting a 2" group offhand with a rifle at 100 vs 200 yds. You see where I'm going? And then when you vary the allowed speed, in addition to target size and distance, you have a complex "problem."

Basic vibe - On an IPSC target, I'd say it's at least 3 or 4 times harder to hit the A box at 25 yds than at 7. To hit the A box at the same distances in 2 seconds, for example, I'd say it's about 3 to 4 times "as hard" as well.

Anybody?

be

[EricW]

Brian,

I think you're right.  It's exponential and the difficulty should increase with the square of the distance.  This is because the relative area of the target is decreasing.

[Math Mode ON]  

The distance subtended by an object is described by the equation:  

Height = Distance x Visual angle.

(Same equation goes for Width.)  

So, for an object of constant height, but placed twice as far away, the visual angle will be 1/2 of the closer one.  No magic here, but because it's really the available "area" of the target that makes things "hard," it's really A = L X W, i.e.  (1/2)*(1/2) = 1/4 as big a target.  So, the 50 yard target has 1/4 the relative area of a target at 25 yards.  Make sense?  

Now for the equation:

Relative Difficulty = (Target Distance/Reference Distance)^2

Using 25 yards as a reference distance, here are some factors for relative difficulty of the shot:

 7 yd - .08  i.e. 8% as tough as at 25 yds

10 yd  - .16

15 yd  - .36

25 yd  -  1 - no surprise here

50 yd  -  4  

This obviously doesn't account for draw time & a bunch of other stuff, so this can't be the only criteria for how "hard" a shot is, but it may a start.  Or, it may not.  

Eric

[Ron Ankeny]

InTheBlack:

I shoot and ride snowmobiles with one of the firearms trainers for our Game and Fish Department. We have had several discussions along the line of your question. Brian is right on with his observations (any suprise there?) but I think your real task will be coming up with realistic par times.

My state (Wyoming) just adopted a new course of fire (Peace Officer's Standards) for handgun and it is coming under attack from all sides. I shot the course and found that some of the times, like 2 seconds to draw from a level 3 holster and hit the 8 inch center ring at 7 yards was way too restrictive for the average shooter. I also found the the times allowed at 10 and 15 yards were way to liberal and could be cut in half. I don't have an answer for you but I do know that you are undertaking a daunting task.

I have been asked to set up several stages next month for a gathering of Game and Fish law enforcement personnel and I intend to set up what you would expect to see at a regular old IPSC match. I am going to make about 4 "short" to "medium" field courses of varying levels of difficulty and we will just score the regular way. The trainer's intent is to show that firearms training can be enjoyable and need not be "threatening". He also wants to show that some folks actually do this stuff for recreation. It should be a load of fun and a real pleasant break for the guys and gals.

I am real interested to hear what you come up with and I'll share your thoughts with my trainer buddies. Please keep me posted.

[InTheBlack]

The targets we use-- Q targets, the Q type that has the circle in the head & chest for higher scoring, B-25 type black silouhettes.  Right now all we have are wooden frames with cardboard to staple them, but we can, say, fold the B25 in half and pretend its behind a barricade.  We also set up bowling pins sometimes on a 2"x6" 'fence rail.'  We use the frames as barricades & notional walls/halls.

I have to get hold of the scoring formula; I've not memorized it but basically it divides points score by time after subtracting 1/2 second/shot as a 'par.'  A stage only allows a specified number of shots.  Then each stage is normalized to the best score, so the top shooter on a stage scores 100%.  Then the match score is the average of all the stages.

Hopefully we're going to do some things, like make a ramp with a rope-pull relase to roll tires with pie plates in them for moving targets.

[benos]

ITB,

Wow, you've got some crazy stuff going on there. Sounds like fun.

EricW,

That's cool - a physical calculation that coincides with a "vibe."

be

[EricW]

BE,

I'm impressed that you intuited that the function was exponential.  I had linear stuck in my head until you said that.  Now it all makes sense.

E

[midvalleyshooter]

I like time plus scoring. The time to do something is your score. Penalties or hits outside the A ring add time. Low score wins. This is a very easy method of scoring and versions are used in IDPA and Cowboy action. If you are interested go to IDPA.com and check out Vickers count scoring.

Keith

[Duane Thomas]

The method of scoring I always thought made the most sense - and I've only seen this at a few local "indoor pistol league" matches - was score minus time, high score wins. Think about it: you have to be accurate to get a high raw score, then the faster you can shoot that high score, the less you get taken away from it - high score wins. It's easy to calculate the final score, and it MAKES SENSE.

[InTheBlack]

That sounds like they are shooting at a bullseye target with scoring rings of differing values.  A Q target has only two relevent values - hit or miss.  How many seconds corresponds to a "hit?"  There needs to be some presumed normalization; like an IDPA "two shots within two seconds drawing from concealment."  We are not playing an IPSC type game where you add to your score for every hit you put on the target.  You are only allowed a specified number of shots at a target, perhaps required to be in a particular pattern such as "two to the body and one to the head."

Our presumed normalization is 1/2 second per shot required.  Raw score is hits divided by the time over the norm.  Then IIRC the high scorer gets a score of 100% and the others a fraction based on that.

[Duane Thomas]

If you're not recording the time to complete each stage, obviously this scoring system won't work.

[InTheBlack]

We record the stage time.  If you take 12 seconds and had to shoot 10 rounds, your normalized time would be

12 - (10 x 1/2) = 7 seconds.