Does Deliberate Practice Make an Expert

Answer to the question

Does deliberate practice make an expert?

Not by itself. Deliberate practice is necessary for skill, but it does not decide who reaches the top. In a 2019 violin replication, the best players had logged fewer practice hours than the good ones. Across 88 studies, practice explained about 12 per cent of performance variance overall, from 26 per cent in games to under 1 per cent in the professions.

Key takeaways

• Ericsson and colleagues (1993) studied 30 violinists in three groups of ten at the Music Academy of West Berlin. By age 18 the best group had accumulated 7,410 hours of practice alone, the good group 5,301 and the less accomplished group 3,420.
• Macnamara and a colleague (2019) repeated the design with 39 students in three groups of 13. Practice alone by age 18 averaged 8,224 hours for the best group and 9,844 for the good group, a gap that was not statistically significant. Current weekly practice was significantly lower in the best group.
• Macnamara and colleagues (2014) pooled 88 studies. Practice explained about 12 per cent of the variance in performance overall: about 26 per cent in games, 21 in music, 18 in sport, 4 in education and under 1 in the professions.
• Ericsson (2016) and Ericsson and Harwell (2019) argue the meta-analysis stretched the definition. Their reanalysis puts the share at 29 per cent, and 61 per cent after correction for measurement unreliability.
• Syed (2015) adds a feedback condition and rests his case on Beckham's practice. A single success cannot show how much of the result practice produced.

In a replication of the best-known study of deliberate practice, the violinists rated best had logged less solitary practice by age eighteen than the group rated merely good, and were practising fewer hours each week. Deliberate practice still matters. What the evidence does not support is the claim that it makes an expert, or that hours alone separate the best from the good. The claim holds up better in some fields than in others, and the dispute over why turns on a definition.

Two Violin Studies Compared

In everyday use, deliberate practice has come to mean any hard, repeated work. The original definition is narrower, and the studies below turn on that difference.

Anders Ericsson and two colleagues published the original, in Psychological Review. They studied thirty violinists in three groups of ten at the Music Academy of West Berlin, rated best, good and less accomplished. The authors named the kind of practice that tracked the gap deliberate practice: solitary work, set up with a master teacher, with goals and methods chosen to improve specific weaknesses.

The 1993 figures were these. By age 18 the best group had accumulated an average of 7,410 hours of practice alone, the good group 5,301 and the less accomplished group 3,420.

Brooke Macnamara and a colleague repeated the design in 2019 with 39 violin students in three groups of 13. The best and good groups were nominated by faculty at the Cleveland Institute of Music, and the less accomplished group came from the music department at Case Western Reserve University. The procedure was double blind. Accumulated practice alone by age 18 averaged 8,224 hours in the best group, 9,844 in the good group and 4,558 in the less accomplished group. The gap between the top two groups was not statistically significant.

Current weekly practice sharpened the result. The best group reported 22.7 hours a week and the good group 30.7, a difference that was statistically significant, with the best players practising less. Across the three groups, accumulated deliberate practice accounted for 26 per cent of the variance in performance, against 48 per cent in the original study. The authors describe 26 per cent as not inconsequential, and say it does not support the original claim that practice largely accounts for performance level.

They also list their own limits. The sample is small, though a third larger than the original, retrospective estimates run high, and groups this accomplished may differ in expertise from the Berlin sample, which would fit practice mattering less near the top. Teacher-designed practice, the element that makes practice deliberate in the original definition, explained no more variance than practice alone, 23 per cent against 26.

By age 20, both top groups had averaged more than 10,000 hours. That is the figure Malcolm Gladwell's Outliers popularised as a rule, as the replication's authors tell it, and in this sample it did not separate the groups.

Syed's Case and Its Limits

Matthew Syed's Black Box Thinking sits nearer Ericsson's side. After describing chess grandmasters, tennis players and paediatric nurses who perform well after years of practice, it says these findings "have led to the conclusion that expertise is, at least in part, about practice (the so-called 10,000-hour rule)" (p. 49). Then it adds a condition. A golfer practising in the dark could carry on "for ten years or ten thousand years" without improving, he writes, because no shot returns any information, while chess players and nurses get fast signals when they are wrong (pp. 49 to 50).

That condition makes Syed's account about the quality of practice and not its quantity. It matches the feedback element in Ericsson's definition. For the concentration half of the claim, see [Why Attention Residue Lingers at Work](https://thewhyweproject.com/articles/why-attention-residue-lingers-at-work). The same question about perseverance is taken up in [Grit Is Mostly Conscientiousness](https://thewhyweproject.com/articles/grit-is-mostly-conscientiousness).

The book's central case is the footballer David Beckham. As a boy he managed five or six keep-me-ups at first, reached 50 after six months and 200 six months after that, and by nine could keep a ball in the air 2,003 times (pp. 270 to 271).

A single success cannot say how much of the result practice produced, because it has no comparison with players who practised as hard and did not reach the top. The violin replication supplies that comparison in miniature. Groups with similar hours ended in different rating bands.

What 88 Studies Add

A 2014 meta-analysis led by Macnamara pooled 88 studies. Across all of them, practice explained about 12 per cent of the variance in performance. Variance explained is the share of the differences between people that a factor accounts for, so at 26 per cent in games, roughly three-quarters of the differences lie elsewhere. By field the figures were about 26 per cent in games, 21 in music, 18 in sport, 4 in education and under 1 in the professions. Education and the professions are the two fields with the smallest shares.

Measurement mattered too. The summary of the paper reports that the practice effect was weaker when practice and performance were measured more precisely, for instance with practice logs and standardised performance scores. Macnamara put the conclusion this way: "Deliberate practice is unquestionably important, but not nearly as important as proponents of the view have claimed."

Deliberate practice is unquestionably important, but not nearly as important as proponents of the view have claimed.

The larger shares in games and music, where errors show quickly, fit Syed's feedback condition, though that reading is an interpretation and the meta-analysis does not isolate feedback. A low share does not by itself point to talent or genes as the remainder. Ericsson makes that point in later work, covered below, and the meta-analysis authors suggest instead that the age at which people start an activity and working memory may account for part of the rest. For a related question about whether practising one task carries over to others, see [Do Brain Training Games Work](https://thewhyweproject.com/articles/do-brain-training-games-work).

Ericsson's Objection: The Definition

Ericsson's reply is that the meta-analysis measured the wrong thing. In a 2016 commentary on a sports meta-analysis by Macnamara and colleagues, he argued that deliberate practice had been stretched to cover group activities, watching games on television, play and competition. Summing hours of any practice, he wrote, implies that the impact of all types of practice on performance is equal. He called for longitudinal studies that track objective performance over time, to identify which practice conditions actually produce improvement.

In 2019 he and a co-author reanalysed the data with three criteria for reproducible performance and purposeful practice, excluding effect sizes that failed them. Practice then explained 29 per cent of the variance, and 61 per cent after correction for measurement unreliability. They also recommend that future studies measure the quality of practice, such as concentration and problem-solving, and not only its duration. That is the same emphasis as Syed's feedback condition.

Both readings are fair, and they answer different questions. Ericsson is asking what happens when deliberate practice is measured as he defined it. The meta-analysis authors are asking how much practice of the kinds people actually report explains.

The definitional objection is sound: a meta-analysis that counts structured practice is not a direct test of the 1993 theory of deliberate practice. The violin replication is closer to a direct test, because it kept the original design and the original split between practice alone and teacher-designed practice. We side with the replication's reading. Demanding practice separates the less accomplished from the rest, who had logged roughly double the hours. At the top, the evidence in hand does not show it separating the best from the good. In these data, hours explain the first step only.

Common questions

Does deliberate practice make an expert?

It is necessary and it does not decide who reaches the top. In the 2019 violin replication, the best players logged fewer hours than the good ones. Across 88 studies, practice explained about 12 per cent of performance variance overall, from 26 per cent in games to under 1 per cent in the professions.

What is the 10,000-hour rule?

It is the popular claim that about 10,000 hours of practice produces mastery. The 2019 replication's authors cite Gladwell's Outliers as the book that popularised it. In their sample, both top violin groups averaged more than 10,000 hours by age 20, and the hours did not separate them.

Does practice still matter, then?

Yes. The less accomplished violinists had logged roughly half the practice of the other groups, and practice explained 26 per cent of the variance across the three groups. Ericsson's reanalysis, restricted to practice that fits his definition, puts the share at 29 per cent, and 61 per cent after correction for measurement error.

Sources

Ericsson, K. A., Krampe, R. T., & Tesch-Römer, C. (1993). 'The role of deliberate practice in the acquisition of expert performance.' Psychological Review, 100(3), 363-406. doi:10.1037/0033-295X.100.3.363

Macnamara, B. N., Hambrick, D. Z., & Oswald, F. L. (2014). 'Deliberate practice and performance in music, games, sports, education, and professions: A meta-analysis.' Psychological Science, 25(8), 1608-1618. doi:10.1177/0956797614535810

Macnamara, B. N., & Maitra, M. (2019). 'The role of deliberate practice in expert performance: revisiting Ericsson, Krampe & Tesch-Römer (1993).' Royal Society Open Science, 6(8), 190327. doi:10.1098/rsos.190327

Ericsson, K. A. (2016). 'Summing up hours of any type of practice versus identifying optimal practice activities: Commentary on Macnamara, Moreau, & Hambrick (2016).' Perspectives on Psychological Science, 11(3), 351-354. doi:10.1177/1745691616635600

Ericsson, K. A., & Harwell, K. W. (2019). 'Deliberate practice and proposed limits on the effects of practice on the acquisition of expert performance: Why the original definition matters and recommendations for future research.' Frontiers in Psychology, 10, 2396. doi:10.3389/fpsyg.2019.02396

Association for Psychological Science (2014). 'Becoming an expert takes more than practice.' News release on Macnamara, Hambrick & Oswald (2014). The 88-study count, domain percentages and the quotation are from this release, read 2026-10-26.

Syed, M. (2015). Black Box Thinking: Marginal Gains and the Secrets of High Performance. John Murray. Pp. 49-50 and 270-271, read from the vault's OCR of the page photos.

Gladwell, M. (2008). Outliers: The Story of Success. Little, Brown. Named as the source of the 10,000-hour rule by Macnamara & Maitra (2019); not consulted directly for this article.

Related concepts

• The 10,000-Hour Rule
• Deliberate Practice

People

• Anders Ericsson
• Matthew Syed
• Malcolm Gladwell