Statistical Nerds League (SNL)

[blethenstrom]

Believe it or not there are nerds wherever you go. You will even find them in a shaving forum like B&B. I thought it would be time for us to find a place to discuss the fine art of statistics when it comes to shaving and shaving hardware/software. Indeed we will probably break many standard statistical rules in the process, but when fun is there if we do not push the envelope a bit.

We are a bit strange and weird bunch of folks, but maybe there will be some useful information that will come out of some of the analysis. We will discuss shave rating criterion, what information to record and most importantly how we interpret the data. This is a place to geek out. Let the inner Lambda Lambda Lambda come out!

If you feel so inclined to join the pocket protector bunch of folks please feel free to add "SNL" to your signature. We would be honored to have you.

 

[Guido75]

Fully in of course! Signature immediately updated. Thread on watch status. Let the games begin!!

 

[blethenstrom]

Fully in of course! Signature immediately updated. Thread on watch status. Let the games begin!!

Fantastic my friend. Let the games begin..........

 

[blethenstrom]

I have been recording my shaves in a log since Aug of 2023 so I have not been at this that long yet and I am sure that there are many others who have shave logs that go way much further back than that. We all have to start somewhere and sometime right?

The most important is that for us to do some sort of a shaving log that can be used to later on do analysis on needs to have numerical scores/values that we can assign to each shave. Being an engineer by trade I did this from the very beginning. Now the bigger question is: what do I record and what rating criterion do I use? After all wet shaving is very much a YMMV endeavor so what good will all this do anyways?

Well the first point is that the shaving log and shaving statistic that you do is foremost and mainly for you and not others. However, as time goes on in this thread we can discuss ways to somehow unify or find a way to compare scores and statistics between each other. I am not sure we will be successful, but even if it is on a limited scale it would be great.

If you decide to keep some sort of a shave log/rating system what tools do you need? I decided even though I have access to Excel to use Google Sheets, which is a free online spreadsheet tool and that has very similar functionality to Excel. This way if I wanted to share my spreadsheets and such I could do that easily as well. If you are really fancy and want to use a database or dedicated statistical tools more power to you.

What do I record in my shave log? Well this is very personal, but we should try to think about how we want to use the data in the future and what kinds of analysis that we would like to do. This step might be the most critical of them all since if we miss something here, once we have recorded 100s of shaves it is very difficult to add something. Now the flip side of this is that you do not want to make it too cumbersome either so that you find entering the shave into the shave log too much work and you end up not doing it. Oh yes keeping a shave log takes a bit of discipline(which I need a bit of in general).

More to follow......

 

[cranewarrior]

I have spent hundreds of dollars already on razors, blades, and soaps, so the reality of saving money from wetshaving is long gone. That said, I enjoy the mental exercise of calculating a per shave cost. I definitely would log acquisition cost and how many usages I got out of each item.

 

[blethenstrom]

I have spent hundreds of dollars already on razors, blades, and soaps, so the reality of saving money from wetshaving is long gone. That said, I enjoy the mental exercise of calculating a per shave cost. I definitely would log acquisition cost and how many usages I got out of each item.

That is something that I personally do not track, but could absolutely be something that could be. Also how long blades last for you, number of shaves for a soap to be used up are other possible points. The most important though is to start with a good solid shave log that stores the needed information to accomplish those things. As long as that is clear you can do all those scenarios.

 

[blethenstrom]

Let us start looking at what to potentially put in our record. Please note that you can put anything that you would like in your records. The world is your oyster. This is just what I put in it. Just keep in mind what you would like to calulate/perform statistics on and you need to have those items in there at least.

Boris's Shave Log Record. I had to split the view into two pictures because it got large.

First we have:

• Shaves - Simple enumerated number. Just to give each shave a unique shave number.
• Shave Date - Pretty self explanatory. Date when shave occurred.
• Time of shave - I just have an AM or PM here if it was morning or evening. On rare occasions I do a quick pass in the morning and then a full shave in the evening. Not really needed from a statistical stand point.
• Number of passes - I have found this field be more useful lately than I thought it would be. You see when you rate a shave you will naturally not have the same shave quality when you only do a single pass vs a three pass shave. This field can be used later to help looking at things.
• Blade - This is the razor blade that was used for the shave. I recommend that you implement this as a lookup table field so that you are consistent on the blade name. Otherwise this can cause problems later.
• Blade Shave # - This is the shave count on that particular blade. Very important field. Just enumerated number for each shave use of that blade.
• Brush - Shave brush used. Also here I recommend a look-up table for brushes.
• Razor - Razor used for the shave. Look-up table recommended.

• Soap - Shave soap used. Look-up table.
• After Shave - After shave used. Look-up table
• Shave Comfort - This is my first rating field and if you want to add other fields please do so. I only have two rating fields and the rest is calculated data. I use a scale of 1 - 10. 10 is most comfortable. Shave comfort rating is just that. How comfortable was the shave? Do I have irritation or other side effect from the shave? etc etc
• Shave Comfort Z-score - This is a calculated value based on Shave Comfort rating. I will discuss this at a later time.
• Shave Quality - This is my second rating field and again add or change rating fields as you see fit. I use a scale of 1 - 10. 10 is BBS, 9.5 DFS++, 9 DFS+, 8 DFS, ....... , 1 is beard to the floor. I will go through my scale a bit more later.
• Shave Quality Z-Score - Calculated field and we will look at that later
• Shave Rating - Average of "Shave Comfort Z-score" and "Shave Quality Z-score". Overall shave score you may call it. You can also do like an average of all your shave ratings. It is up to you.
• Notes - This is just......notes about the shave.

These are the fields that I have for my shave log. You may like them dislike them, but they are my fields. You do your fields and we will be off to the races. I do all my statistics based on these fields. The shave log is the most important thing if you want to perform analysis on your shaves. Even if you have not worked out what to do analysis on yet, you still need a log or records as it is called. Work on that while we work out the other pieces.

If you would like to attempt to implement a shave log and have questions please feel free to ask questions.

 

[cranewarrior]

This seems like a fun idea to play with, building a frontend to make data entry easier into the Google Sheet.

 

[blethenstrom]

This seems like a fun idea to play with, building a frontend to make data entry easier into the Google Sheet.

Absolutely a front end can certainly help the entry of the shaving records.

 

[cranewarrior]

Absolutely a front end can certainly help the entry of the shaving records.

I run Linux as my primary OS, and I'm used to QT-based applications. This seems like a natural side project for me as if I don't have other more pressing things to do. LOL.

 

[blethenstrom]

I run Linux as my primary OS, and I'm used to QT-based applications. This seems like a natural side project for me as if I don't have other more pressing things to do. LOL.

Absolutely! You can even make cool analysis in Python. It has some many libraries to do really neat things. You can just use Google Sheets as a storage area.

 

[Guido75]

I run Ubuntu at home. I fiddled around with R this weekend but for some reason wasn’t thrilled with the results. Python didn’t want to load the panda or statmodels - as Alex mentioned a nice side project (which I can really use right now of course!!).

Cheers,

Guido

 

[Guido75]

In terms of outliers by the way - the KCG and RFB seem to be the least effective at the moment. I need to control for blades (hey! new input! Whoop whoop!) see if that makes a difference.

Guido

 

[blethenstrom]

This is today's statistical nerds update.

How do we rate our shaves?

When you come up with your ratings there is a few things to keep in mind. First your ratings are your ratings and none others. Ratings that you are entering in your shave log cannot be compared with another persons shave ratings because it is very subjective. This also means that unless you do some massaging of your statistical data it is difficult at best to compare statistical outcomes.

The only thing you have to keep in mind while setting up your rating scale is to try to be as consistent with YOURSELF as you can be. This is the only person you have to be consistent with to eventually gain some useful information. Now this may seem easy, but we change over time as well and we may also drift in our judgements of our shaves over time. Just keep this in mind. It is probably a good idea to draft up some sort of a scale that you can follow.

For me the "Shave Quality" is a bit easier because you can actually put it on a scale that has some sort of measurements. the below picture shows what my scale looks like. Now you come up with your own. Maybe you want to only use a 5 step scale, maybe you do not like the way I named the steps, great name them something different. the important thing is that you try to make it as objective as you can for yourself and then stick to it.

If you change scale or rating system after a while, you will find yourself in a bit of a dilemma. You will not be able to do statistical analysis on all your shave log as a unit. You may have to treat the pre and post rating change records differently. If you a lucky you can translate one rating scale to another, but many times this is not possible either and you are stuck dealing with them separately.

How do you rate your shaves? Please share.

 

[Guido75]

Mine is as follows:

Rating	Sharpness	Quality	Comfort	Effectiveness
10	Insanely sharp	Clean	GlideFest	BBS+ / Marble
9	Wickedly sharp	Red spots	Buttery smooth	BBS
8	Crazy sharp	Multiple weepers	Smooth	BBS-
7	Very sharp	Nick	Comfortable	DFS
6	Razor sharp	Cut	Tuggy	DFS-
5	Sharp	Multiple cuts	Harsh	CCS
4	Sharp Edge	Divot	Pulling	CCS-
3	Working Edge	Multiple divots	Uncomfortable	SAS
2	Working Dull	Sweeney	Stop shaving!	SAS-
1	Dull	Sweeneys	Stop shaving!	No shave

 

[Guido75]

I began transferring 2022 from my journal to my spreadsheet. That should result in overall shave statistics of some 650+ shaves.

 

[blethenstrom]

I began transferring 2022 from my journal to my spreadsheet. That should result in overall shave statistics of some 650+ shaves.

That'll give you plenty of records to play with.

 

[blethenstrom]

Mine is as follows:

Rating	Sharpness	Quality	Comfort	Effectiveness
10	Insanely sharp	Clean	GlideFest	BBS+ / Marble
9	Wickedly sharp	Red spots	Buttery smooth	BBS
8	Crazy sharp	Multiple weepers	Smooth	BBS-
7	Very sharp	Nick	Comfortable	DFS
6	Razor sharp	Cut	Tuggy	DFS-
5	Sharp	Multiple cuts	Harsh	CCS
4	Sharp Edge	Divot	Pulling	CCS-
3	Working Edge	Multiple divots	Uncomfortable	SAS
2	Working Dull	Sweeney	Stop shaving!	SAS-
1	Dull	Sweeneys	Stop shaving!	No shave

I still need to come up with a good shave quality rating. Mine is too loose at this point.

 

[blethenstrom]

Here is my first stab at a Shave Comfort rating

What do you think?

 

[Guido75]

Here is my first stab at a Shave Comfort rating
View attachment 1843218
What do you think?

This is not bad at all! Interesting too - your Comfort rating is more my Quality rating and Comfort rating combined. Nice!

You could turn 7 into Nick to have a distinction between weeper and weepers.