The deliberate part is so often overlooked since most people only know training with a teacher, where they give the responsibility for the deliberate part to the teacher without even knowing.

If you start learning by yourself from every 10 hours of practice maybe only 1-2 might count as deliberate. If that efficiency is tracked as well, one could argue that even a motivated learner might take up to 20k hours to get to his 10k hours of deliberate practice.

Interesting theory, but is it backed by anything other than supposition?

Longitudinal, crossectional pilot studies at least?

I have the same google that you have (assuming that you don't live in a country with a "Secret Special Google" project).

What you find feel free to share it here for others to read. :)

I'm sorry, how does history require fewer hours than chess? Are you a historian or chess player? What does history 'performance' even mean?!

The parent said history may take more hours.

I don't know much about chess, but fields like software and math are analogously low on information volume compared to history, making a much lower baseline on hours for good talent. I'd say musical performance, likewise.

This is why I love computer science but hate chemistry. Too much volume.

If the volume bothers you, you can work mostly in moles...

That normalizes away, because the hours required is based on relative comparison to others, not some objective measure of talent across fields.

Math has low information volume, but it is slower information. A good historical treatment of a topic may be 2000 pages, and a good math treatment of a topic may be 100pages, but both requiring the same amount of time to study and comprehend.

The thing with math is it's very variable depending on talent. Maybe that's the case with history too. In one grueling math class I took, the ratio in time spent on problem sets between the kids who might become math professors and the best kid in the class was about 3. And it was only that low because the problems were really dirty. For history, I don't know what that's like. For software, the training time ratio is even bigger because the bar for "expert" is so low, and the knowledge required to start creating good software is small. As for chess, I thought it required a lot of study to play at a GM level.