Randomising wear and tear of safety razor

A few months back, having mostly given up on my Gillette Mach 3, I decided to go all old school and get myself a safety razor. While I cut myself occasionally (one day I cut myself right on my Adam’s apple, giving me a minor scare that I’d slit my throat), I’m significantly happier with the results of this razor, compared to the Mach 3.

I find that I need to shave only a single time, compared to two rounds with the Mach3, and cleaning the razor in the middle of the shave is also far easier. And while it isn’t absolutely smooth, it leaves me mostly satisfied at the end of the shave. And I’m not even mentioning the cost saving here!

The only “problem” with using an old-school safety razor is that it takes in double-edged blades. Having used multi-blade cartridges all my shaving life thus far (my father had bought me a Sensor Excel when I was first ready to shave, which I later traded for a Mach3), I started using a single side of the blade to complete the entire shave.

In my experience, a decent blade should last about 6 shaves, as long as you use both edges of the blade equally. The challenge here was to know (visually) which side of the blade you had used, so that you could get the maximum out of the blade!

Initially I thought of using stickers or some such paraphernalia to indicate which side of the blade I’d used each time. After a little thought, however, I realised that if this was a common problem, the razor itself would’ve come with an asymmetrical head, so I could keep track. There should be a better way to keep track, I reasoned.

And so I decided that I would use each edge of the blade half-and-half in each shave. The first day, it worked. The second, I had finished shaving half my face, when I realised I’d suddenly forgotten which side I’d used. An improved method was required.

So the solution I’ve finally hit on is to randomise the edge of the blade I use each time I rinse my blade in the middle of the shave. So each time I rinse the blade, I give it a random twirl, and use whatever edge that twirl turns up for my next set of strokes. And so forth. This way, in terms of expected value, both edges of the blade are likely to wear by a similar amount by the end of each shave!

And so if I find one day that an edge is blunt, it is highly likely that the opposite edge is also as blunt, and it is a clear indication to put in a new blade!

It is remarkable how so often randomised algorithms can help you trivially solve problems that cannot easily be solved by deterministic methods!


This Monday, for the first time in my life, I got myself shaved by a hajaam (barber). Yes, for the ten-odd years that I’ve been shaving, I’d so far never let anyone put a blade on my face. However, a long vacation in Bangalore, absence of my usual Mach-3 and constant jibes by my mom about “wilderness on my face” led me to the hajaam.

I started off my shaving career sometime in 1999 when I was presented a Gillette Sensor Excel. After I earned my first ever salary (four years back) I upgraded myself to a Mach 3. I’ve had a few flings with cheap one-piece razors such as the Gillette Presto or the 7 o’clock Ready 2 Shave, but till a week back had never put a single blade on my face. It was always at least double. And I’d always do the act twice, once forward and once “reverse”. And for all these ten years, the part of the process that has taken the maximum time has been to ensure that my sideburns (I’ve always had them) are of equal length.

The act of getting shaved itself was pretty quick, maybe since it was so much easier for the hajaam to figure out if my sideburns were of equal size, or maybe since he didn’t care about it as much as I do. It was a bit uncomfortable as his hands, one of which held an ultra-sharp single blade, hovered over my face and neck. It itched a bit, and my face twitched a bit, but thankfully I didn’t get cut. It was again a “double shave” but unlike my own double shaves, both the shaves that the barber did were in the “forward direction”. Maybe the barber’s single blade isn’t suited for “reverse shaving”.

In the two minutes that I spent getting shaved, I started thinking of the history of shaving (no I’m not talking about the series of communist portraits here (Marx-Lenin-Stalin-Mao) ). About how if I’d been born a century earlier I’d have to go through this hajaamat on a regular basis – since safety razors weren’t yet in existence then. About how certain Hindu customs have failed to take into account the development of the safety razor and the fact that one can shave himself easily now. I was thinking about the total amount of business that barbers would have lost thanks to King Gillette’s invention – rather than making their money out of a daily shave, they now had to rely on monthly hair cuts only.

Another thing with the invention of the safety razor is that full beards are now less popular – back in the days when everyone had to go to the hajaam for a shave, people couldn’t afford to shave daily, and a full beard appeared significantly better than a stubble. Now that people can afford to shave daily, they never have a stubble and can thus be always clean-shaven.

The most uncomfortable part of the shave was when the guy was shaving the upper lip. With the nose on one side and the mouth on the other I was quite scared. I now reason that the coming of the safety razor has played a significant role in the decreasing popularity of moustaches – you feel so much more comfortable taking care of that sensitive region yourself rather than handing it over to a hajaam.

It was overall a quick, mildly scary, but decent experience. I got charged Rupees Twenty which I thought was okay for the shave. And I realized how much higher the barber’s “billing rate” was for the shave (twenty rupees for five minutes’ work) as opposed to a haircut (fifty rupees for twenty minutes’ work) . And I started wondering once again about the damage to barbers’ fortunes caused by King Gillette’s invention.