How to Tell If Your Sensei Is Good

“Eureka!”, “Eureka!”

The legendary shouts of Archimedes echoed throughout the streets of Syracuse, as he ran around town naked, yelling “I have found it!” – so excited by his new scientific discovery that he had even forgotten to dress.

In case you skipped history class in high school, Archimedes of Syracuse (287 BC – 212 BC) was a Greek mathematician, physicist, engineer, inventor and astronomer. Although few details of his life are known (besides his infamous “Eureka!”-run through town), Archimedes is regarded as one of the leading scientists in classical antiquity. Among his discoveries in physics were the foundation of statics, hydrostatics and an explanation of the principle of the lever – along with some pretty innovative machines (including siege engines and screw pumps).

Those old Greeks were so nifty!

Today, Archimedes is considered one of the greatest mathematicians of all time. But his greatest discovery would never have taken place if it wasn’t for his king.

And, coincidentally, the learnings from that particular discovery process can actually help you determine if you have a good Karate sensei or not.


Allow me to explain:

As the story goes, some 2,200 years ago, King Hieron II of Syracuse (in Sicily) gave a goldsmith a bar of gold and ordered him to make it into a crown. Said and done, the goldsmith delivered a swagged out crown a couple of weeks later, but upon closer inspection the king suspected that the goldsmith had substituted some of the gold in the crown for cheaper metal like silver.

However, the king had no way of proving his suspicion. So he asked Archimedes – the most famous scientist in the hood – to find a definitive answer for him.

Archimedes accepted the challenge.

The problem proved trickier than anticipated though, and Archimedes studied day and night to find a solution.

Nothing seemed to work.

But then, one morning when Archimedes was about to take a bath, he suddenly realized something. As he slid into the bathtub, some water would always flow over the brim. The more Archimedes sunk down in the tub, the more water splashed out. In fact, the volume of displaced fluid seemed to be equal to the volume of the submerged bodyparts.


Since Archimedes knew that gold was denser than silver, if a certain weight of silver had been substituted for the same weight of gold in the crown, the crown would occupy a larger space than an identical one of pure gold.

Archimedes swiftly jumped out of the bathtub, got the crown, immersed it in the tub and measured the spillage. Then did the same procedure with an exact amount of real gold – if the goldsmith had indeed made a crown of pure gold, the volume should be the same.

It wasn’t.


Archimedes had not only discovered what we today know as Archimedes’ Principle (“Any object, wholly or partially immersed in a fluid, is buoyed up by a force equal to the weight of the fluid displaced by the object.”), but he also proved that the goldsmith was indeed cheating the king.

Case closed.

History made.

The funny thing about this story is that, even though Archimedes took baths all the time, he would probably never have discovered this scientific principle if it wasn’t for his king’s request to solve this particular problem.

Archimedes was literally immersed in the answer every single day.

He just needed somebody to ask him the right kind of question.

And this, dear Karate Nerd™, is what every great Karate sensei on earth knows.

“A good teacher can never be fixed in a routine. Each moment requires a sensitive mind that is constantly changing and constantly adapting. A teacher must never impose his students to fit his favorite pattern. A good teacher protects his students from his own influence. A teacher is never a giver of truth; he is a guide, a pointer to the truth that each student must find for himself. I am not teaching you anything. I just help you to explore yourself.” – Bruce Lee (1940-1973)


You see, what characterizes a really good sensei is not so much his grades, lineage, style, dojo, titles, awards or number of students.

(Not even what kind of car he drives.)

What characterizes a good sensei is the amount of times he makes you realize that you’ve had the answers to your questions all along.

Inside you.

And that’s how you know if your sensei is good or not.

It’s all about being gently nudged out of your comfort zone, day by day, class by class, technique by technique, (often without even noticing it) until you suddenly hit that incredible insight that pushes you over the tipping point – making the discovery overflow your “bathtub of Karate”.


Next level.

Just like Archimedes.

The best Karate teachers often make you think “this is stupid” again and again and again, until you suddenly get that “aha”-moment… and finally realize why you had to go through those seemingly “stupid” exercises all along.

Forcing you to realize that you already had the answers inside.

You just needed somebody to bring them out of you.

That’s what a great sensei does.


But that’s not all.

The best part of what every sensei does can be illustrated with another quick historical tidbit; namely the story of Christopher Columbus’ Egg.

Ever heard it?

The story goes like this:

After finishing his journey to the Americas, putting another continent on the map for the Europeans, Columbus was attending a dinner banquet with his Spanish buddies back home. During the dinner, a comment was made by one of his guests that Columbus’ achievements were not all that exceptional and that “anyone could have discovered a continent as big as the New World” given enough time. Indeed, Spain had a lot of talented sailors and generals in those days, and many others could probably have achieved what Columbus did.

Nonetheless, this got Columbus pissed off.

So he asked for an egg.

Holding the egg in his hand, Columbus challenged the other guests to balance the egg upright on the table. Everyone tried. Everyone failed. Columbus, amused by his guests’ attempts at the challenge, finally took the egg himself and tapped its end until the shell cracked a bit. Now the egg could be placed on the table without falling over.

The guests looked at Columbus in amazement.

Minds = blown.

The moral of the story? Things always seem hard to do until you know how to do them. And once you discover how to do something new, everyone else will learn it too. The difficult part is just getting there.

That’s exactly what a good sensei is for.

So when you find one, make sure you cherish each insight.

Because your sensei doesn’t only elevate you.

He elevates us all.


  • Chase Smith
    Hi Jesse-san. Interesting article, and for once, I actually might have to disagree a bit ;) >t’s all about being gently nudged out of your comfort zone, day by day, class by class, technique by technique, (often without even noticing it) until you suddenly hit that incredible insight that pushes you over the tipping point – making the discovery overflow your “bathtub of Karate”. This is all well and fine, but I do believe it renders karate as too subjective. Comfort zones vary, but does good karate? I see your rebuttal, which might state, isn't good karate supposed to push the comfort zones? Of couse, but I don't think that this is merely the case. Many things can push one out of their element, but karate is special due to the way it is done. A good sensei will teach karate in a manner that teaches one to fight, but also cautions against frivolously engaging in combat. What separates karate sensei from 'yellow bamboo' instructors if all we need is our boundaries pushed? Anyways, those are my thoughts. Thanks for the thought provoking Article Jesse-san. OSU
    • Chase-san, Thanks for your thoughtful comment. You write "What separates karate sensei from ‘yellow bamboo’ instructors if all we need is our boundaries pushed?" My reply? Nothing. But... what separates a good sensei from 'yellow bamboo' instructors is the direction he pushes you in. Makes sense? Thanks again for chiming in!
  • Dave Chisnall
    My Sensei @ kaizen do karate in Rochdale is a fantastic teacher of karate. I started karate at the age of 39 after my son who has autism started in may 2011. Sensei Dervish and his fantastic team of Sensei's are in my opinion absolutely amazing. Alex has just gained his brown belt of which I am so proud if him for persevering with something that is way out of his comfort zone. I'm getting better at this amazing sport and hopefully getting better and will be taking the next grading in may for my brown belt also, my daughter had just achieved her blue belt just before she starts university. Thank you karate for giving my family something we all love to do as a family. It's hard work sometimes but the support and friendship we have at Kaizen Do karate is absolutely first class. I would urge anybody in the world to give it an opportunity. You won't regret it. Dave.
  • Jesse San Very insightful article You are very talented and I enjoy your website Keep up the excellent work Warmest Sandy
  • Boban Alempijevic
    Love history, it can always teach one how to loof forward by looking at what came before you and learning from it, hopefully not from the mistakes though :D
  • keith varias
    Thank you for another great article. Sensei should NEVER FORCE YOU TO take his path. Instead help us realize our own path.
  • Arian
    This reaffirms what I've already known for the past 22 years: my sensei is as good as they get.
  • I'm confused... so if my Sensei invites me over for a dinner of eggs and to take a bath -- which is outside my comfort zone-- I should go?
    • Most definitely, Ando-san! Just make sure to bring a groin cup and mouthguard, because things might get hot n' heavy. ;)
      • I already wear a cup and mouthguard 24/7... I'm married.
  • Chip Quimby
    Nicely written, Jesse! I can feel my boat rising now, wink wink. As far as comfort zones go, I think it's incumbent for all teachers to sincerely challenge their students; and this would include encouraging them embrace those things which are personally uncomfortable; physically, mentally and spiritually. I think it’s part and parcel of authentic martial arts training. At least it is for me. As I see it, having the conviction to confront the self, for all it might [and might not] be, is where the real growing begins. I see it as an on-going and dynamic process.
  • Madelyn
    Oh WOW!! As an aspiring one-day future sensei, this is just so insightful. Really soaking it in!
  • Jack M
    A really good sensei smiles if you correct him.
    • Florian Pean
      a really good sensei not only smiles but thanks you for correcting him, as a good sensei learns from his students as much as he teaches.
  • Mario Bonetta
    Couldn't agree more with Bruce Lee description. I continuously tell my student not to take any teaching as set on concrete. Simple things like your body size, height or psychological or spiritual make will make techniques and approaches different form student to student. I also encourage them to take an existential approach to it and try to adapt things to their own make. You got to be able to see if it works FOR YOU. than the lesson is not a lesson anymore, it becomes a place of sharing and exchange.
  • Mike
    "Bath tub of Karate". That should be on a t-shirt. Also, excellent article. Thanks.
  • Maddox
    Hi Jesse my dad told me about your site and I am amazed about how much you do! I just got my blue belt last night and I finally can tell my teacher about you. Keep up the good work on this site and I will favorite it. :-)
  • David Alexander
    AWESOME post as always Jesse-San!!! Thanks to you, I can now tell whether my Sensei is a good one or a total fake. By the way, who's your Sensei, Jesse-San?
  • David Alexander
    Jesse, You're Swedish?!?!( I'm just curious,deeply sorry if this offends you)
  • tony christopher
    Hi, I'm 66yrs old and pretty fly for a white guy, had two knee ops, minor surgery, in pain, always at physio. So started karate again, been back 4 months, feel great!, looking good. Got my my shodan in 1988 with sensei Asano nottingham. I agree with your theory of bieng pushed closer to the edge and doing stupid basics over and over, but it pays, I didnt really feel I could punch until I got my shodan, then 'bam' it all came together. Never too late to train Karate !!!. Tony Christopher Sheffield
  • Maximiliano
    It doesn't matter how old are some of your publication, they keep amusing me. Thanks for sharing the winsome

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