The Perfect Double

[C Sims]

I'd agree, sure is allot of talk about a guy that doesn't even have a last name, Mike ?

Must sure be an important dude

Flex runs with the important high class crowd, I should have known that he would be talking about this Mike character.

[EricW]

I can't believe we've had 4 pages about a Mike.

No sh*t. The UN has passed major resolutions with less debate than this.

[Vince Pinto]

Gorilla,

Rather than having a lengthy arbitration process on these "immaculate" doubles .....

You cannot arbitrate a scoring call and the appeal process which is allowed usually takes 5 minutes, even if the RM is a Fat Bastard ©

[mactiger]

Hey, Vince, I resemble that remark!

Guys, use the overlays, call it like you see it, and get on with it. It's a game--nobody wins a year's salary or a new Mercedes, Hummer, <insert prize of your dreams here>, for winning first place. Y'all have a Merry Christmas.

[TheOtherErik]

I vote we drop this never ending debate and more on to a more important one. http://www.brianenos.com/forums/index.php?...opic=10068&st=0

[BritinUSA]

Assuming that a top shooter hits the 'A' of an IPSC target 90% of the time...

The 'A' zone is 15 x 28 centimetres, or 150mm x 280mm. A total area of 42,000 mm2

An IPSC overlay has markings approximately 1mm thick, so any hits that are less than 1mm apart would be very hard if not impossible to determine. To obliterate an entire 'A' zone with hits exactly 1mm apart would require approx 38,211 9mm bullets.

Assuming that 90% of the hits are in the 'A' zone then 42,456 overall hits at the target would be required to ensure a duplicate hit somewhere on the 'A' zone.

Further assuming that the average 'big' IPSC match is in the order of 250 rounds then it would require 42,456 / 250 rounds to get a perfect double. (ie. less than 1mm difference).

This means that in theory a top shooter who averages 90% 'A' hits with every shot would need to take part in nearly 170 major matches before they would get a perfect double.

In other words if you can't see two holes then chances are that it is a miss, the odds of it being a double are 42,456 to 1.

Or something like that...

[C Sims]

BritinUSA, what are you a secret double agent Math genius with too much time on your hands. You lost me after the first 38,000 + 9mm holes.

Good job figuring it all out!

[Flexmoney]

Two things:

- Our overlays (mine anyways) are bigger than the bullet. And, the hole in the cardboard shrinks some after a bullet passes thru it. The double would NOT have to be perfect.

I think we could fit quite a few bullets into the confines of an overlay.

- The odds of putting two bullets close to the same spot increase when that is the actual goal of the shooter. Most of the time, that isn't the goal. But, in the stage I meantioned, going for two Alphas in the head might mean that the top shooters are more inclined to strive for accurate hits.

[Vince Pinto]

Hi guys,

No matter how you cut it or argue it, if you do indeed have a 100% perfect double, an RO can do nothing but score it as a Miss, because a 100% Perfect Double cannot, by definition, be detected.

And Flex is perfectly correct - unless the competitor is using wadcutters, there's a high probability that a 99% perfect double will be detectable, because the hole on the target is usually smaller than the calibre used, which is why I continue to encourage ROs to do their very best to examine the possibility. In fact, I've started carrying a 10x jeweller's loupe in my range bag to assist me in this task (and that should turn a few heads the next time I'm asked to check a hole).

However the bottom line is the same: If you can't see it, then it's just not there and you cannot, and must not, award a hit by using "benefit of doubt". It would be unfair to all the other competitors.

Flex,

I suggest you get a better set of overlays. I've checked mine (the ones previously available from the IPSC website), and the holes are exactly the correct diameter. Moreover, I can't even precisely measure the lines of the circles because they're so thin but, as far as I can determine, the lines are 1/3 to 1/4 of a millimetre wide.

[shred]

Schuemann tried the math a while ago to prove the 'impossibility' of a double, but again he also assumed an even distribution of shots throughout the entire A-zone. You need some sort of weighting towards the center of the A-zone. Take a look at the back of a target after a bunch of good shooters have been by-- the really punched-out area is usually much smaller than the entire A-zone.

You also should address the 'birthday paradox'-- the odds of two shots in the same hole is much larger than the odds of perfectly obliterating the A-zone.

The perfectest double I ever saw was shot by Miculek at Area 4 one year. He only asked that the target pulled because it was an A-zone surrounded by no-shoots and they were clean. It looked exactly like Alpha-Mike as it sat on the target stands. Once it was pulled it still looked like Alpha-Mike until the cardboard around the hole was flattened out, then you could barely see both grease rings. There was less than 1mm separating them.

[Flexmoney]

No matter how you cut it or argue it, if you do indeed have a 100% perfect double, an RO can do nothing but score it as a Miss, because a 100% Perfect Double cannot, by definition, be detected.

That, actually, was my original question....I think.

How do you score the double? (any guidance in the rulebook?)

Vince, I agree that we can't start giving them out on the "benefit of doubt" theory.

However, I'm not sure where in the rule-book that this is explained.

Earlier, I pointed out that the rulebook stipulates a visible hit for a penalty target. I don't see that distinction for a scoring target.

After all...a hit that goes thru the same hole, is still a hit. And, the rulebook doesn't care what the odds are.

If we stipulate that each scoring hit needs to have it's own visible mark on the target...then the whole idea of a perfect double goes away.

[Vince Pinto]

Flex,

OK, so we're on the same page, and I've made a note to add the words in bold below to the next revision:

9.4.1 Scoring hits visible on the scoring area of* IPSC targets will be scored in accordance with the values approved by the IPSC General Assembly. (See Appendices B and C).

* to be defined elsewhere.

-:but I must confess that we assume a certain level of intelligence among the huddled masses, and we really didn't think it was necessary to state what our British friends would call "the bleedin' obvious" but apparently (and very sadly) we were wrong. Then again, judging by some of the questions asked here (e.g. "Can I run up the side berm and shoot over the top of the props?" and "Can I shoot a target from the rear?"), I start to fear for our sport.

I'm also trying my best to avoid having a rulebook you need to carry around in a wheelbarrow, and the 2004 Edition actually has fewer words than it's predecessor but, at the rate we're going, I think I better apply for a discount card at Home Depot.

Anyway, we primarily added the word "visible" to penalty targets to deal with metal targets, so that competitors wouldn't be penalised just because somebody "heard" a hit on a penalty popper.

[Flexmoney]

"...on the same page"...yikes, that can't be a good thing.

The revised 9.4.1 looks great.

And, I agree. We are blessed to be able to share time with a pretty smart group of people.

This little tweak just serves to get our RO's out of what could be a "tight spot".

With the change, it won't matter how positive the shooter is that they shot the "perfect double". The RO can simply say that there aren't two visible marks to score. (And any shooter that can hit "doubles" on a regular basis ought to be able to space the hits far enough apart so that we can easily see them to score them as two seperate hits. )

In the interest of savings a word...you could remove the first "Scoring", then transpose "hits" and "visible".

As such:

9.4.1 Visible hits on the scoring area of* IPSC targets will be scored in accordance with the values approved by the IPSC General Assembly. (See Appendices B and C).

[Joe D]

I had it happen to me about a year ago. There was a close target, 5 yds, that was shot from a static position. It happened to be the next to last target, only the head was visible. My first shot was a center A. When I fired the second shot the front sight was centered on the first shot hole. I remember hoping, after I shot the second shot, that the RO watched to see if the target moved. I thought maybe the hole would be slightly elongated. It was scored as a miss. One of my fellow squad members said he had seen both bullets impact in the same spot on the berm. I asked the RO to look at it again, but no go, I had to go with his decision.