Price-adjusted Blade Ranking

[bonusmarple]

What might be interesting is to develop a way for other users to add their impressions, or else develop their own ratings. And I'd want to devise a more simplified metric, say the price per blade divided by the number of shaves. But I do understand a need for the adjusted score, but only because I sometimes paid attention in my stats classes.

The second option would probably be a better, easier path, come to think of it. And I may do up my own--with NOS blades only--of course.

The price used is the price per shave, not per blade. There are a few NOS in there, but those are an interesting class unto themselves.

 

[jpkunst]

I don't believe I can attach a spreadsheet so I broke out the items and pasted them below.

Why not put it in a shared Google Docs spreadsheet?

 

[DunEdinRanger]

How would getting 100 Astras for $11 affect the results?

 

[bonusmarple]

Why not put it in a shared Google Docs spreadsheet?

Done, great suggestion, didn't even know this feature existed.

http://spreadsheets.google.com/ccc?key=0Anjekho6QUx-dDlqZmV4YWlKZUIzSmsyWDZOcTZBQkE&hl=en

 

[bonusmarple]

How would getting 100 Astras for $11 affect the results?

They stay tied for 20th. One other item is how many shaves do you get out of it. I will pm the spreadsheet out or you can go out to the google link where I posted the doc.

 

[bonusmarple]

Added the google link to the wiki. In the razor blade section under external links.

 

[Topgumby]

This might well take some of the mystery and magic out of the blade preference game and make it more a matter of science.

In fact, looking at if from a mathematical perspective, I think maybe the way to go would be with two, or maybe even three, four or five blades at once.

 

[le_paulo]

This is an awesome resource for us newbies. What a great idea!

 

[sparkster123]

i was looking at the spread sheet and saw you had put down in the squire rating a 7.5 for perma sharp supers and i have not seen where squire has even reviewed this blade.

if he has can you point me to this link. these are a great blade by the way.

randy

 

[bonusmarple]

i was looking at the spread sheet and saw you had put down in the squire rating a 7.5 for perma sharp supers and i have not seen where squire has even reviewed this blade.

if he has can you point me to this link. these are a great blade by the way.

randy

A few posts back I had a blurb about those ratings. Basically, they are from squire where he has the rating, from elsewhere where he does not. I am going to change the heading on that column to other ranking since it is 90% squire and 10% others. I have a feeling this question will come up frequently as this gets used more and this will save some confusion on everyone's part.

 

[Jonnie]

I am on vacation. I don't know if that is better or worse than doing this at work.

Either way it all just depends on if your boss finds out.

What's really funny (sad?) is that I put together something like this on my own several months ago when looking at benefits of DE shaving. Came up with pretty much the same numbers as you have.

From looking at the definition, I don't really have OCD, guess I'm just more just "Extreme Obsessive"? What is it called when you do things like blade/cost spreadsheets, measuring the aggressive gaps of razors http://wiki.badgerandblade.com/index.php/Double-Edged_Safety_Razors_Ranked_by_Aggressiveness, etc.? At least I'm in very good company! (BTW, I'm not making fun of the aggressiveness study!! I think it's great and kind of interesting that the Progress has a much wider range than the Futur does.)

 

[Stubblefield]

There are a few NOS in there, but those are an interesting class unto themselves.

Perhaps I need to toss up some NOS reviews.

 

[Jwolf24601]

Now I just gotta figure out how to apply double the emphasis on cost with that...

 

[siouxsie]

I applaud the effort and I urge you to add Blue Birds to the equation. They are superb and available reasonably priced on the 'bay. I think once you and Squire try them they will definitely land in the top 5-10 AT LEAST.

 

[StillShaving]

Keep in mind that the second ratings column was from Squire, where he had ratings. For the other values I used best guess. Perma-sharp Supers are very similar for me to Iridiums, so I used that rating. That disclaimer aside, here is the formula.

Raw Score = (Ranking Source 1 + ... + Ranking Source N) / N
Price Adjustment = 1 - cost per shave
Price Adjusted Score = (Price Adjustment) * (Raw Score)

Thanks a lot for the data and posting the spreadsheet. Not to second guess your methods but I noticed that the price adjustment, e.g. 1 - cost/shave is the overriding factor in the calculation. With some small minor exceptions this meant that the cost adjusted ranking is the same as the non-price adjusted rating. One could chose a different calculation, or using this same calculation chose a different baseline such as $0.25 versus $1.00 and get a good bigger variance in the price adjusted numbers. I am not saying that any particular baseline is best, just that the output is really dependent on the formula. It is not clear to me what would generate the most unbiased output, as this is clearly a situation of YMMV and whether you view the blade rankings on an absolute or logarithmic scale or what your total budget is when trying determine the best blade on a price adjusted basis.

Also what does the acronym PIA mean?

 

[goby]

I applaud the effort and I urge you to add Blue Birds to the equation. They are superb and available reasonably priced on the 'bay. I think once you and Squire try them they will definitely land in the top 5-10 AT LEAST.

Not only do I agree with the Bluebirds, but I love that picture of Siouxsie.

 

[chilliman64]

did we ever find out what the PIA acronym stands for?

 

[HoosierTrooper]

did we ever find out what the PIA acronym stands for?

I'm guessing that after 31/2 years everyone sort of forgot about it.

 

[bonusmarple]

PIA should have been PA for Price Adjusted. It was a typo.

 

[dmurach]

I see there is already a Google docs version, but I already had it formatted, so.... here you go:

Name,Rating,Squire Rating,Quantity,Quantity Price(USD),Number of Shaves,Per Shave Price,Raw Rating,PIA Rating
Feather,9.5,8,200,70,4,0.0875,8.75,7.984375
Perma-sharp Super,9.25,7.5,100,28,6,0.046666667,8.375,7.984166667
Iridium Super,9,7.5,250,58,7,0.033142857,8.25,7.976571429
Gillette 7 O'Clock Yellow,9,7.5,200,56,7,0.04,8.25,7.92
Gillette 7 O'Clock Green Permasharp,8.75,7.25,100,38,5,0.076,8,7.392
Gillette 7 O'Clock Green Super Stainless,8.5,6.75,120,23,5,0.038333333,7.625,7.332708333
NOS Wilkinson UK White Box,8,7.5,100,22,4,0.055,7.75,7.32375
Shark Super Chrome,8,6.85,100,16,5,0.032,7.425,7.1874
Shark Super Stainless,8,6.85,100,17,5,0.034,7.425,7.17255
Kai,8.5,7,100,30,4,0.075,7.75,7.16875
Gillette Swedes,8.5,6.75,100,62,10,0.062,7.625,7.15225
Dorco ST-301,7.5,6.63,400,35,4,0.021875,7.065,6.910453125
Super Max Platinum,7.5,6.75,100,21,4,0.0525,7.125,6.7509375
Super Max Super Stainless,7.25,6.5,500,41,3,0.027333333,6.875,6.687083333
Bolzano,7.5,7.5,100,53,4,0.1325,7.5,6.50625
Wilkinson Economie,7.5,6.25,125,35,4,0.07,6.875,6.39375
Crystals,6.5,6.75,100,16,4,0.04,6.625,6.36
Dorco ST-300,7,6,100,10,4,0.025,6.5,6.3375
NOS Gillette Thin,8,7.5,10,8,4,0.2,7.75,6.2
Astra Superior,6.5,6.25,100,17,4,0.0425,6.375,6.1040625
Wilkinson India,7,6.85,5,2.75,4,0.1375,6.925,5.9728125
Red Pack Personnas,6,6.25,200,20,4,0.025,6.125,5.971875
Astra Keramik,6,6.75,100,33,4,0.0825,6.375,5.8490625
Derby,5,7,200,25,4,0.03125,6,5.8125
Greek Bic,5,6.75,100,19,3,0.063333333,5.875,5.502916667
Sharp,5,6,200,29,3,0.048333333,5.5,5.234166667
7 "AM",4,6.5,200,30,3,0.05,5.25,4.9875
Treet Platinum,2,6.75,200,33,4,0.04125,4.375,4.19453125
Treet Classic DuraSharp,1,7,200,25,2,0.0625,4,3.75
Merkur Platinum,2,2,10,6,4,0.15,2,1.7
Wally Personnas (new release),1,1,10,1.79,4,0.04475,1,0.95525