how far an amateur can go?

GM Becerra just flat out lied. Well if you could actually spend 8-10 hours (which he could do I bet but he's a GM!) a day maybe 2 or 3 years but very few people can do that.

Ludicrous claim, "... anyone, a GM in a year," though Lasker claimed that any person of average intelligence could become a master.

Unless by 'GM in a year' we mean that we'll pay a few dozen titled players off to lose to you. Could probably be done in less than a year with enough money. Not that I'm implying that anyone would actually take money to lose a chess game.

(This in no way is meant to disrespect the truly vast majority of players who have worked hard and honestly to gain titles. I truly respect each and every one of them for that very notable achievement. I concur with Natalia's bs observation, as well. And, note the teasing emoticon at end of paragraph above.)

 10,000 hours is the magic number that's often quoted for the time it takes to become world class at a skill, probably including chess. That's hours of effective training - the right thing for you.

If we say a year has 250 8-hour working days, that'd mean 5 years of that. But probably more becasue it's hard to keep going that consistently, and your training method probably isn't as good as it could be.

Would depend some on what one means by the words, but the 10,000 hours thingy is commonly used in reference to mastery. I would personally put the term world class in another category above that one, a category reserved for those who are on another level altogether. Perhaps, Top 5 or Top 10 GMs would be such a group. Anyway, I would use it to refer to those who are truly gifted beyond simply practiced.

But Scar's point is made. Takes a lot more than 2,000 hours to crank out a GM, even with a prodigy involved.

try with 2000games/year for at least 4years, but it greatly depends on the start

 I agree that its bullshit and also think GM Becerra just doesnt want to discourage any prospective students. I think one must have some talent to reach GM level and without that talent no amount of work will ever make a club player a GM. Don't kid yourselves !

How far can an amateur go in chess ? Is an amateur simply one who isnt a chess professional ? If so then look at Max Euwe, he was world champion and an amateur. I think it hard to answer such a question since so many will not agree on the definition for "amateur".

Well the definition of amateur chess player is a person that is not living off chess. You become a professional in any sport when you start earning enough off it to live off it and start doing so.