How much did you improve with a coach?

How much did you improve after you began to work with a coach? Let's say after 6 or 12 months?

Which were the lessons that had the biggest positive effect on your game? I am interested in anything you can say in the topic.

I don't remember very much, but I got a coach when I was, maybe 1000? 3 years ago, I am now 1700 USCF

Thank. Did you work long with this coach? 

I mean of course "thanks"

I am still working with him

I improved 1000 points in a year, but I only started playing in tournaments when i started being coached and had played chess long before, so the resutls may be a bit skewed

After 1 year i got from mid 1500s to 1800-1900 range

I didn't improve much. He gave me homework to do (like puzzles and certain games to go over all of which he provided), but I didn't do it, so it's my fault.

its not only up to the coach to make you improve, its a 70/30 I improved from 1000 to 1800 with a coach but I used to practice everyday, other guys who had my same coach improved from 1000 to 1400 and in the same time that I use (3 years) if you want I am giving a free leson, just message me so you can see how I teach

Which was the main part of the work?  Strategy?  

I guess the main improvement occurs in the first years, after eliminating the basic blunders and typical innacuracies. 

tactics, lots of attacking openings, endgame knowledgr etc.

Okay, I guess tactics I can do alone, and endgames too. I think a coach would be a big help in showing the right way how to analyse  my games.

It is better if you  play endings with coach. 

You mean even if I work with a book like Jesus de La Villa's "100 Endgames You Must Know" ? I can imagine that a coach would show me how to go for exchanges to reach a certain endgame and things like that, right? 

I went from barely knowing a single way to put my pieces, back rank mates, and absolutely nothing else to playing in tournaments and winning money and getting first place trophies nearly once a month. That was after just a couple months with him

A coach is useful, and definitely someone you want on your team if you can afford it.

A very good alternative, however, is to train with someone about your level, who preferably has different strengths than you. With this person, (online or OTB) you can practice endgames, get motivation to complete problems, and analyze games together. Best of all, it costs nothing, as they are learning as well. This arrangement gained me my last 375 rating points, from low 1800s to low 2200s.

@torrubirubi Practicing endgames with a coach typically means taking one side of a theoretical ending and your coach takes the other, and you practice it OTB to make sure you've mastered it.

I see.  My problem is always that I am afraid to commit myself to work with a coach. I think that a coach  will probably make more sense if I begin to play OTB in a club and play tournaments. I don't play in a club, only online or with weaker friends.