Most people assume that the gap between the good and the great comes down to talent. Two people put in the same hours, one soars and the other stalls, and the easy conclusion is that one of them simply had more to work with. It’s a tidy explanation, and it has shaped a long debate in psychology.

A study published in Psychological Science this year points somewhere else. What separates achievers from ultra achievers may have less to do with how much they practice, or how gifted they are, than with one specific habit : going back to study their own mistakes.

The Chess Experiment That Revealed This Habit

The story begins with chess, which has long served as psychology’s favorite laboratory for expertise. Early research found that grandmasters don’t have superhuman memories. What they have is a vast library of patterns built up over years of study.

In the 1990s, the psychologist K. Anders Ericsson took that insight further with his theory of deliberate practice . His argument was that expertise doesn’t come from experience alone. It comes from a particular kind of practice that is focused on a clear weakness, paired with immediate feedback and repeated until the weakness is fixed. Ericsson’s work later inspired the popular “10,000 hours” idea, though he felt that slogan left out the most important part, which was the type of hours.

Then came the pushback. Critics, including researchers behind an influential 2014 meta-analysis , found that practice explained less of the difference between people than Ericsson’s theory implied, and argued that innate ability deserved more credit.

Ericsson’s side countered that many of those studies lumped all practice together, counting casual play the same as focused training. The disagreement was hard to settle, because most of the evidence relied on people’s memories of how they had practiced years earlier.

The Study That Could Finally Tested The Habit

That’s what makes the new research, led by psychologist Daniel Southwick with colleagues at Brigham Young University and elsewhere, unusual. Chess.com gave the team records for more than 44,000 players who joined the site in March 2024, and the researchers followed them for six months.

Instead of asking people how they trained, they could see it frist hand. Every rated game played, every lesson watched, every puzzle attempted, every past game reviewed, alongside how each player’s rating changed. They also registered their predictions in advance, before testing them.

The results were clear. Hour for hour, time spent on focused study activities was linked with roughly three and a half times as much rating improvement as time spent simply playing games.

The most reliable of them was reviewing one’s own past games. That meant replaying the moves, finding where things went wrong and trying the position again. Game reviews were more than five times as efficient as play, and they were the only activity that beat play at every skill level, from beginner to advanced.

And yet players spent about 90% of their time just playing.

The Habit Of ‘Studying Your Tape’

This is the achiever’s instinct at work. Playing feels productive . It’s fun, it’s active, and it produces a steady sense of motion. Reviewing a loss, by contrast, means sitting with a mistake you would rather forget.

Ultra achievers make a different trade. In the study, the highest-rated players devoted several times more of their time to reviewing their games than beginners did. They treated each error as information rather than as something to move past. It’s the same habit seen in athletes who rewatch game film, surgeons who debrief after a difficult case and writers who reread the draft that didn’t work.

What may make the habit powerful is how closely it matches the conditions Ericsson described. The feedback is specific to you. The weakness is concrete, and you can try the same situation again until you get it right. Simply doing the activity again, by comparison, tends to repeat the same mistakes.

This Habit Changes The ‘Talent Vs. Pratice’ Debate

The study’s most provocative idea concerns a well-known pattern called the “fan-spread effect.” People who start out ahead often pull further ahead over time, which is often read as a sign of natural ability.

The researchers suggest that at least part of that widening gap may reflect practice habits instead. Using the study’s numbers, the authors modeled three hypothetical players with the same starting rating and the same total hours. Their projected paths split sharply, depending only on how each divided their time.

The authors are careful about the limits. The study observed people rather than assigning them to practice methods, so motivated learners may differ in other ways too. It couldn’t track coaching or play that happened off the site. And most players were recreational rather than elite.

Still, the lesson travels well beyond chess. Achievers ask how they can do more. Ultra achievers ask what went wrong last time, and then go back to find out.

Do you study your mistakes, or just replay them on a loop out of habit? Find out whether your mind turns errors into lessons or into rumination with this science-backed test: Mistake Rumination Test