Couldn't find Silman's explanation but Coach Heisman thinks you should be over 1700:
How To Reassess Your Chess and the How to Reassess Your Chess Workbook– Jeremy Silman – How to use imblances to figure out what to do. The books I would recommend after reading Amateur’s Mind. See Silman's recommendations on book order. The first 52 pages of HTRYC (3rd ed) is much more basic than the remainder. The 4th ed. of HTRYC is clearer and more focused. Recommended once you no longer play "Hope Chess" and lose material to unseen threats (USCF 1600+)
Encyclopedia of
Here's a link to Coach Heisman's web site and book recommendations:
http://danheisman.home.comcast.net/~danheisman/Events_Books/General_Book_Guide.htm#anthologies
The full book title is How To Reassess Your Chess. I had to shorten it because the topic space wouldn't let me type that long of a question. Do you even need to be a 1400 player to read it? If so, why?