What should I study next?

What area of chess should I study next?  The choices are Openings, Tactics, Positional Play, and Endgame.  Please read the description of my current chess status/knowledge before making me a recommendation.

My details:

Rating: Around 1500-1600 (High Class C, Low Class B).  Do not look at my chess.com ratings, as I only play short games here where I do not pay much attention to what I am doing.  I play my serious games elsewhere.

Openings: I have a repertoire for White with 1 e4, using the Ruy Lopez as a base.  I also have repertoires for Black against both 1 e4 and 1 d4. I understand the general principles of all the openings that I play regularly. Further study here would involve concrete memorization and analysis of lines.

Tactics: Around 1550 on chess.com Tactics Trainer.  Regardless of what I am studying next, I will continue to do Tactics Trainer puzzles daily.  I will also do additional puzzles as I see fit.  Therefore, if you say I should "study tactics," to me, that doesn't mean to do more tactical puzzles but rather to study combinational motifs, sacrificial play, mating patterns, and calculation.

Positional Play: I have read Silman's "How to Reassess Your Chess," Nimzowitsch's "My System," and am finishing up Watson's "Secrets of Modern Chess Strategy."  Therefore, I feel I have a strong foundation in positional play.  Further study might include reading over examples of Nimzowitsch's theories or reading some of Aagaard's books on strategic/positional play.

Endgames: I have read Silman's Endgame Course, Class E and Class D.  My endgame play though is generally rather weak, especially Rook and Pawn endgames and Endgames where I need to push pawns (e.g. Not R+K v K).  Potential candidate books that I might read to study endgames include: Silman's Endgame Course (Class C and maybe Class B sections), "Essential Chess Endings" by Howell, and "Chess Endings: Essential Knowledge" by Averbakh.

I look forward to seeing your recommendations.  Thanks.

Definately endgames.  Averbakh is a legendary endgame author so you can't go wrong with the essential knowledge one.  Fundamental Chess Endings and 100 Endgames You Must Know are also highly recommended.  Don't forget about endgame strategy, which is the transitional phase from middle to endgame.  Shereshevsky's Endgame Strategy then move onto Secrets of Endgame Strategy by Bo Hansen. 

After that move on to Muller's How to Play Chess Endgames, but that will be over a year away assuming you study things other than the endgame within that period too. 

All one needs methinks is Laslo Polgars giant chess book.

Its the everything in one book kinda book.

I think the great thing about problems is that it trains you to think.

I recomend thinking instead of knowing stuff.

You don`t even need to remember a single problem from the book.

It will be like running since your legs will be stronger but you don`t need to remember where to put your feet.

Tactics for the Advanced Player, by Averbach.  You are at the proper strength and have the proper attitude to really appreciate this classic.  It will help both your endings and middlegames, and help streamline your calculations.

If you have Silman's Endgame course you've got an all purpose book up to master level (everything you need) still I'd suggest either getting one or a couple of books covering Rook Endgames (very important)

These are the best I know all are worth the money I have them at home.

1000 Rook Endings by Jozsef Pinter

http://www.newinchess.com/1_000_Rook_Endings-p-1521.html

Pinter is the best if you can find his book anywhere used or new get it!

Practical Rook Endings by Victor Kortchnoi

http://www.amazon.com/Practical-Rook-Endings-Progress-Chess/dp/3283004013

You should be about 1700-1900 before reading his book he doesn't spoon feed prepare to work if you want to get this one

Rook Endings by Grigory Levenfish and Vassily Smylov

http://www.amazon.com/Rook-Endings-Grigory-Levenfish/dp/0713403543/ref=sr_1_sc_1?s=books&ie=UTF8&qid=1391904811&sr=1-1-spell&keywords=smylov+rook+endings

You want the 1970's copy stay away from the green copy of the book from 1989 has lots of typographical errors.

Practical Rook Endings Edmar Mednis:

http://www.amazon.com/Practical-Rook-Endings-Edmar-Mednis/dp/0931462169/ref=sr_1_sc_1?s=books&ie=UTF8&qid=1391905153&sr=1-1-spell&keywords=medins+practical+rook+endings

I got this book when I was a kid and I still have it I recommend it highly to beginners and intermediate players production wise no frills but for 70 pages he packed it with good stuff. Activate the Rook and keep it activate magic words!

I'd suggest the next two chapters of Silman's endgame book and a ton of tactics (both fast tactics for patterns and slow tactics for calculation & board vision; use Chesstempo for slow tactics).

You might find this book useful.

http://www.amazon.com/Chess-Exam-And-Training-Guide/dp/0975476122

Thanks.

How many long games (minimum 4h) have you played after reading all these books ? If the answer is less than 30, and I pressume it is, I suggest you don't open any more books and start to play OTB long games (with stronger players).

As a chess coach and international master I can recommend you to study the classics. Alekhine legacy I and II are great books (I'm not sure if they are available in English), 300 chosen games from Alekhine, the timeless Zurich International chess tournament 1953.From these books you will learn a lot, but very careful study is required. 

For calculation I recommend Think like a grandmaster from A. Kotov

For endgames, Theory and practice of chess endgames by Panchenko.

The last two books can be quite difficult, so it is advisable first to study the games of Alekhine, or Capablanka in order to get good fondation

I have studied Capablanca, but not Alekhine.  Perhaps I should look into studying Alekhine's games.  IIRC, Kasparov said that Alekhine was one of his big inspirations.

Is this the Alekhine book?  http://www.amazon.com/Alexander-Alekhine-A-A-Kotov/dp/0713429631

From Alekhine books I learnet the most. I'm not completely sure, bacause I studied from the Russian version, but I think that's the book. Study it carefully 

How do you guys visualize the positions in those books? By having a real chess board next to you?

Yeah or in your head. Strong players can do it solely in their head, I can only do that for short lines.

Just the Facts endgame book by Albert is another level up from Silman's book on the endgame.

I do that too.

Disclaimer: this is coming from a beginner with a <500 rating

Most games will be lost way before the endgame. By then, a better opponent will have some kind of an advantage which converting won't be the big deal for him.

Focus on openings and the middle game. That should see you jump above the 1200 threshhold 

It's amazing for regular training can do. check it out. an hour a day...

Thanks, but as I said in my opening post, my current rating is around 1500-1600.  At that level, endgames are important and my advantage going into the endgame is usually small (e.g. better piece positioning, better pawn structure), and not something like I'm up a minor piece.

really? that is very different than my experience. Until I am playing people 1600+, anything in the 1500s has been a tangible advantage going into the endgame