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.
Tile groups
Tile groups can be broken down into two subcategories: sequential and triplets. Of the two, the former is the easier to complete by virtue of greater tile counts for completion. For every waiting pattern, there is a set number of waiting tiles. Ryanmen provide the greatest number of waiting tiles from using just two tiles. As for other shapes, players may need to consider the ability for the tile shape to be reformed.