One of the most common questions that I get about how to play mahjong is how to choose a mahjong line or hand. (“Line” and “hand” are interchangeable) The trick for me is to not choose a line, at least not right away. Rather than choosing a line, right after the deal, I choose a section.
Mahjong is all about recognizing and matching patterns. Start by organizing your tiles by suit and number order—this will help you to see patterns in the tiles you’ve been dealt.
Once you choose a section, start collecting any tile that fits into the section of the card during the Charleston. As the Charleston progresses, you can start to hone in on a single line/hand that you want to play.
A rule of thumb that I use, if you have 6-7 tiles towards a single line, then that is your line you should choose.