Riichi Book 1
Riichi Book 1 is a "mahjong strategy primer for European players". Written by Daina Chiba, it is a free online guide written in English and is often cited as go-to source for game improvement among the Western player base. The material is aimed to help players learn the game beyond yaku and perhaps attain tokujou level status on the Tenhou ladder.
Tenhou.net
Tile efficiency
The third chapter of the book covers tile efficiency with an emphasis on maximization. Players need to understand that a hand can be broken down into basic blocks. Given various hand shapes, a hand during the process of development always have a number of waiting tiles to further progress the hand. Here, player must look to aim to reduce the shanten count. A lower shanten count reduces the number of waiting tiles. This only means the hand advances and requires fewer tiles to advance further. Once tenpai, the counts are minimized.