In the comments to This War Continues a couple of us have been talking about what it takes to be an expert. I had recently read that it takes three hours per day of training to become an expert.
Those three hours per day are actually an estimate on the number of hours per day to become an expert in approximately ten years. As mentioned by M.C. Elroy, it's actually based on the 10000-Hours-Rule. The 10000-Hours-Rule is a claim made popular in the book Outliers by Malcom Gladwell (make sure to watch the three videos found on the side bar) that 10,000 hours of delibriate practice are required to become an elite expert at any given thing. The idea itself comes out of the work of Anders Ericsson who did studies of what he called elite performance or expertise.
Ericsson lists three very broad ingredients that are need to produce an expert:
1)Measure - Lord Kelvin once said, “If you can not measure it, you can not improve it.”
2) Deliberate Practice - Practice does not make perfect. Repeating what you already know how to do does not help make you an expert. Focused effort to do something you don't do well or can't do at all (called deliberate practice) is the key. 10,000 hours of this and you're on your way.
3) Finding Coaches and Mentors – The best coaches know skills will need improvement at the next level not just your current level and so can help tremendously to ensure deliberate practice.
Batman is currently the 14th most powerful comic character according to ComicVine's Rank Game. He is ranks first in Unarmed Combat, Escape Artist, Tracking, Gadgets and Stealth. Plus he ranks 4th in Weapon Mastery and Marksmanship. According to the 10,000-Hours-Rule, to be an expert in all those requires 70,000 hours or 21 hours per day for 10 years straight of dedicated practice.