depends on if you're serious or not
if you're not serious like me, 10 years
2000+??? That's like <1% of chess players. You have better chances trying to win money betting on horses.
The chess.com engine has serious problems, I just played the 2000 rating computer, thinking for 5-15 seconds for each of my moves and I beat it in 17 moves.
Randomly terrible performance from this engine, for example : The 1600 computer will normally play at 1600 for me, opening, middle and endgame (Sometimes a little stronger in the endgame) but it will randomly play at a 1200 level for an entire game or much higher than 1600, I don't know how the staff set up the computer but this "expert" computer was playing with a 900 rating's skill.
It's not always like this for me, but I suppose since I was moving every 5-15 seconds, it didn't have much time to think (Although I've played against it at that speed several times and this is the first time it's played like a 900, all the other times I've played it, it was normal (Less often) or around the 1600's level (Most of the time). I think this is a bug which needs to be fixed. I'm only around 1300-1400 OTB, this should not be happening. -.-
how many years of experience does it take for the average person to beat the computer on expert? (2000+)