Expertise is recognition and recognition comes from an incredible amount of highly structured information stored in long-term memory, To build that memory you need 4 things-

1. Repeated attempts with feedback:
   Doing the task again and again, attempting it with feedback to check on a scale of 1 to 10, rating you on how well you are doing. If you are a cricket player you can practice the "cover drive" thousands of times, you need to also have feedback each time if your cover drive was good enough.

2. Valid environment: The environment or the task you are working on should have regularities in patterns or how the event is going to occur. No matter how much time you spent gambling you can't predict the Russian roulette table as it depends on probability.
   Read: Warrent Buffett vs Ted Seides
   The stock price is a low-validity environment and you can't predict if it's going to go up or down usually. It doesn't reflect about the quality of decision-making.
   Humans want to see the pattern everywhere including in randomness. We try to beat the average by predicting the pattern. But what if there is no pattern? This will then lead to a terrible strategy.

3. Timely feedback:
   If there are patterns in your art, you need timely feedback to adjust to those patterns. Suppose you are a recruiter for a tech firm and you hire someone today, and it's going to take years before you find out if it was a good hire. Hence it gets difficult to get timely feedback and improve in recruiting good talent. You need timely feedback on wheater or not you are improving.

4. Don't get too comfortable:

   You need to always keep striving. If you get too comfortable with your work, no matter how much you repeat it you are not going to unlock that next level. It's called Deliberate Practice. That's why coaches and teachers are so valuable because they know your current level and they ask you to improve. You need to practice thousands of hours in the uncomfortable grey zone.