Mathematical probability of locating a dropped fly

[springer1]

I was wondering how to calculate the probability of finding a fly dropped when tying it onto your line and came up with this draft formula.

I know it’s not correct because it doesn’t factor in whether you’re color blind which makes a big difference if you drop one on land. However I don’t know how to construct a single equation to take the C variable into consideration, or if the constants are correct, or if other variables are needed.

P = Probability of finding a fly dropped during tying.
W (ading) = Constant 2 if wading, constant 1 if on land.
C (olor blind) = Constant 2 if you’re color blind, constant 1 if not.
R (eserve) = Constant 3 you don’t have another fly like it in your box, constant 1 if you do.
F (eed) = Constant 2 if fish are feeding, constant 1 if it’s a slow day.

........1
------------- = P
..W * R * B

 

[Volksnurse]

Serious math and philosophy....

P= N 0 T_T-A / CH A /\/ C E

 

[JackM]

It was funny after two words. Thereafter-- incomprehensible.

 

[Fishidiot]

Prepare to be "Pcraaaaayed."!

(He should love this one - I'd think)

 

[djs12354]

P = Little to none.

 

[Biggie]

If you use a magnetic net holder, your chances are about 90% success of finding the dropped fly. I am sure I have paid for the magnets already just by retrieving dropped flies.

 

[geebee]

you missed L, L= Length of Grass...

 

[salmonoid]

V = variation in color of fly vs. surrounding environs..

I was hugely disappointed last summer when I was backpacking and left my site in the morning, and I sensed a loss. I was a few hundred steps down the trail when I realized that my deer hair mouse was no longer on my fly pad (AKA rubber zipper pull). I went back to the campsite and after about five minutes of searching over what could have been no more than 16 square feet, I discovered the mouse. Maybe easy enough to see in the picture, but I initially could not locate it that day.

 

[bigslackwater]

I would have never found that...is it in the center of the pic?


This reminds me of something that happened to me last week. I was fishing dry files for the first time this year and trying to place my fly just on the edge of some brush over hanging the opposite bank. The fish were laying right there... On one bad cast I got snagged and rather than spook the fish I gave it a good quick yank and broke it off... I Tied a new fly on and all was well...a little while later I get snagged again. I yanked it back and my new fly had brought back the first fly!! Later I got snagged again in the same spot, and brought back yet another fly, this one was not mine. I was up one fly that day!

 

[salmonoid]

It is in the center of the pic. The fly has sentimental value; it's a deer hair mouse I tied years ago at a fly-tying course I took from Ed Kraft. The only fish it has caught have all been large night-time brownies. I don't know that other flies wouldn't work but I know this one was effective and I did not want to use it. That trip, it was for practical purposes as well - I had no other large flies on my, as I had bought a few at Bass Pro on the trip up, but managed to forget them about six miles out at my vehicle.

 

[fishbaithohaha]

S = constant for size (squared for size18+)

 

[FiveWeight]

A+ Ditto.

Long as I don't drop um in the drink, I find most of um with a magnet.

 

[JeffK]

Just walk bare foot. It is guaranteed that it will get stuck in your foot.

 

[pcray1231]

If you want to be accurate.

P = probability of finding it.
C = color contrast of fly with surroundings (higher means more contrast)
R = Roughness of ground (tall vs. short grass, scattered leaves, etc.; higher means rougher)
A = area (as in how big is the area where you know the fly resides; higher means larger area)
Y = "youthfulness" of your eyes. Just like following a tiny dry fly in a bubble line, some eyes pick out small details better, and this degrades as you age. Higher means your better at seeing small details, lower means "older".
'
D = determination. How much does finding it matter to you? Whether the fish are rising, and sentimental value are included here. Higher means more determined.

See what I did there?

But to put that into an equation, the trends are right with the below equation. There need to be coefficients, but it would take some experimentation to determine them.

P = (C*Y*D)/(R*A)

 

[PennypackFlyer]

Don't forget I = intoxicated (how may flies do you see to how many you actually dropped)

 

[springer1]

So, it's getting to be something like ...


P = probability of finding it.
C = color contrast of fly with surroundings (higher means more contrast)
R = Roughness of ground (tall vs. short grass, scattered leaves, etc.; higher means rougher)
A = area (as in how big is the area where you know the fly resides; higher means larger area)
Y = "youthfulness" of your eyes. Just like following a tiny dry fly in a bubble line, some eyes pick out small details better, and this degrades as you age. Higher means your better at seeing small details, lower means "older".
D = determination. How much does finding it matter to you? Whether the fish are rising, and sentimental value are included here. Higher means more determined.
M = magnetic net holder available
L= Length of Grass...
V = variation in color of fly vs. surrounding environs..
S = constant for size (squared for size18+)
I = intoxicated

.... or....

P = (C*Y*D)+(M*V) / (R*A)+(S*I)+(L/3)

 

[Phish_On]

I found a tandem rig I dropped in a riffle, the other day. Surprised it didnt wash away. Then again. I have eyes like a predatory raptor.

 

[JasonS]

You guys are horrible at math. The probability is obv 50/50. You either find it or you don't.

 

[geebee]

springer1 wrote:
So, it's getting to be something like ...


P = probability of finding it.
C = color contrast of fly with surroundings (higher means more contrast)
R = Roughness of ground (tall vs. short grass, scattered leaves, etc.; higher means rougher)
A = area (as in how big is the area where you know the fly resides; higher means larger area)
Y = "youthfulness" of your eyes. Just like following a tiny dry fly in a bubble line, some eyes pick out small details better, and this degrades as you age. Higher means your better at seeing small details, lower means "older".
D = determination. How much does finding it matter to you? Whether the fish are rising, and sentimental value are included here. Higher means more determined.
M = magnetic net holder available
L= Length of Grass...
V = variation in color of fly vs. surrounding environs..
S = constant for size (squared for size18+)
I = intoxicated

.... or....

P = (C*Y*D)+(M*V) / (R*A)+(S*I)+(L/3)

very good, but you missed out - H , H = How much you need it, ie is it the last one that matches the hatch ?

D could also be separated into D1 - Determined, a positive factor, and D2 - Desparate, an inverse factor.

and A2 - angle of the Sun ....

V is too close to C...

so....


P = probability of finding it.
C = color contrast of fly with surroundings (higher means more contrast)
R = Roughness of ground (tall vs. short grass, scattered leaves, etc.; higher means rougher)
A (1) = area (as in how big is the area where you know the fly resides; higher means larger area)
Y = "youthfulness" of your eyes. Just like following a tiny dry fly in a bubble line, some eyes pick out small details better, and this degrades as you age. Higher means your better at seeing small details, lower means "older".
I = intoxicated
S = constant for size (squared for size18+)
A(2) = angle of the Sun
D(1) = determination. How much does finding it matter to you? Whether the fish are rising, and sentimental value are included here. Higher means more determined.
M = magnetic net holder available
L= Length of Grass
D(2) = desparation.
H= How much you need it....


I think we are almost there... need maybe two or three more variables


:-D