By now you must have heard the "10,000 Hour Rule," the popular belief that mastery in anything is simply a matter of racking up that many hours of practice. That idea -- that any of us could get good at whatever we want --is so appealing, and that 10,000 number is just so perfectly round, it must be true, right?

Let's track down where this 10,000 hour idea comes from and what it really means.

Ten thousand hours enters pop culture with the publication of Malcolm Gladwell's book Outliers: The Story of Success, which profiles successful people like the Beatles, Bill Gates, and theoretical physicist J. Robert Oppenheimer. Gladwell pulls 10,000 hours from the work of researcher Anders Ericsson, boldly stating that "ten thousand hours is the magic number of greatness."

Let's look at who Ericsson is and what his research shows. Ericsson studies how people acquire skills and expertise in different fields. He studied 40 violin virtuosos in Germany, asking them how much they practiced by the age of 20. Answers ranged from 3,500 hours up to 12,000 hours, with 10,000 or so being the average. That's how we get the number.

So what does a study of a small group of musicians tell us about the path to mastery in BJJ or any other endeavor? Not too much. We already know it takes a long time to get good at a complex activity. Ericsson has since published his own book Peak, which refutes some claims Gladwell made by misinterpreting his research. 

It is also important to note that Ericsson has a different definition for "deliberate practice" than most of us. Not all forms of practice count.

A paper from the Michigan State University titled "Deliberate practice: Is that all it takes to become an expert?" says this about Ericsson and his definition of deliberate practice:

Ericsson et al. defined deliberate practice as engagement in highly structured activities that are created specifically to improve performance in a domain through immediate feedback, that require a high level of concentration, and that are not inherently enjoyable. Ericsson et al. distinguished deliberate practice from two other forms of domain-specific experience–work and play–as follows:

Work includes public performance, competitions, services rendered for pay, and other activities directly motivated by external rewards. Play includes activities that have no explicit goal and that are inherently enjoyable. Deliberate practice includes activities that have been specially designed to improve the current level of performance.

Focusing solely on deliberate practice neglects other important factors like genetics, psychology, and socio-economic circumstances. The book The Sports Gene by David Epstein takes a more well-rounded look at how all of these factors interact.

In 2012, I reviewed The Talent Code, a book in the same vein as Outliers (it quotes the "10,000 Hour Rule"). My summary of it is still my favorite way to get to the core of what it takes to get good at anything:

“Get someone passionate about something and make them practice for years under an experienced coach and they’ll get good (unless they don’t.)”

Here’s a quick list of “take away lessons” you can get from reading any of these books on talent:

• The elite got that way through many thousands of hours of diligent practice.
• High repetition is necessary to gain competency in a skill.
• You learn the most by pushing yourself to the edge of your ability and paying attention to your mistakes so you can fix them.
• The learning process is often frustrating and you can’t always tell when you’re improving until you’re put to the test later.
• A good curriculum “chunks” skills together so they are easier to learn, and the chunks get bigger as the student becomes able to handle the earlier ones.
• Students should spend a lot of time watching masters practice and perform.
• Coaches and teachers value hard work and persistence over “natural genius.”
• A good coach establishes an emotional connection with his students so he knows when to be nice and when to push hard.
• You can focus on specific skills by doing drills that isolate it for repeated trial-and-error.
• Those who achieve greatness often started with a humble instructor who fostered a love for the subject.
• Those who see themselves doing an activity for a long time find more time to practice (and therefore get better) than those who only set short term goals.
• Kids who feel talent can be gained through hard work have better problem-solving skills and more determination than kids who believe their intelligence or skill is inherited and unchangeable.
• “Having fun” isn’t the primary goal of people who want to get good, though they find what they do pleasurable on some level (or at least necessary) and push through all the difficulties and challenges.