Part of the book is that experts did NOT necessarily practice more--they practiced in a better way.

This is the whole point of "deliberate practice".

The problem is defining what is "deliberate" for tasks where there is not necessarily an "objectively correct" result.

Studies are easiest to perform on topics with easy to measure results.

But in most any field, if you’re genuinely interested in the field, you will be aware of people who you consider to be better than you. Even if it’s a highly subjective field, as you learn your taste/appreciation grows and you get a clearer picture of what you consider “better”. Those are your potential pool of coaches/mentors. You don’t have to pick just one, either.

Sports demonstrates precisely the opposite. Most experts that are very good at a subject are completely incorrect at describing what is actually going on.

There is a reason why we use cameras, computers and scientists for kinematics at the highest levels of sports.

I think this is a confusion between “marginal” and “by and large”.

If I go to a coach to help me with running faster their advice won’t be “completely wrong” — it will be “by and large” correct.

But there are still opportunities for “marginal” improvements that can be found with better measurements. Eg in moneyball they weren’t showing that everything the scouts did was completely wrong. They showed that marginal improvements could give them an economic edge. Even a few percentage points of improvement of received wisdom v measurement meant their money was much better spent.

> If I go to a coach to help me with running faster their advice won’t be “completely wrong” — it will be “by and large” correct.

Nope. Unless they've been vetted, their advice is rarely better than random. And, even if they've been vetted unless they're biomechanicists, they often have these totally weird misconceptions about some specific thing.

See: baseball pitching. Practically everything about pitching below the major leagues was detrimental to pitchers (and even the major leagues had lots of misconceptions) until the scientists got involved.

What disguises this in sports is that consistency wins out over correctness until you reach the very, very highest levels. The problem is that it is almost impossible to adjust to "correct" after 10+ years of doing it wrong. So, what happens is that those doing it "correct" move on to the next layer while those doing it "incorrect" get left behind.

One example I like because it's so telling: driving. Over the course of their live, people drive a really long time. But after 10k hours, are they racing pilots? (Some drivers can't even park properly...)

Literally the point of Ericsson. The "D" in "DP" is not just there for decoration.

Examples like driving or touch typing are among the most-mentioned examples in the literature for skills where people just go to "good enough" and then plateau, because they don't deliberately aim for improvement.

This misses the point because people are not doing 'deliberate practice' while driving. If they spent their time actively trying to get better each time they drove things might be very different.

The point is that one needs specifically deliberate practice to achieve constant improvement. GP is saying that driving demonstrates this by showing that non-deliberate practice ceases to show improvement fairly quickly.

Looks interesting the book you mentioned.

Have you also read "Atomic habits" by James Clear ?

If you're at all interested in the mentioned book, and you enjoyed atomic habits, then you really ought to read Peak.

improvemnt ~= time-on-task * effectiveness-of-practice

Atomic habits is great on the operational side for systematically allocating time toward your goals. Establishing reliable and sustainable time-on-task.

Peak is great for having a critical framework for how, specifically, you use that allocated time. Optimizing effectiveness-of-practice.