5 Block Theory

5 Block Theory is a pretty standard method of progressing your hand quickly and efficiently. If you’ve never heard of this theory before, you’ve probably naturally familiarised yourself with the basics already. It is the path of least resistance.

Studying the theory itself, though, may help you really absorb it and guide you when the timer is ticking.

The theory was already well popularised in the west by Daina Chiba’s book.

All mahjong hands have to have four groups and a pair which equals five blocks. The material to build those five blocks are dealt to you in your initial hand. I won’t wind all the way back to a starting hand but offer an example that has been progressed somewhat.

If we identify the blocks, we have one too many…

There are two completed blocks with your pair in 2m and a group of 567s. And four incomplete blocks.

5 Block theory means that you have to reduce your hand by one block. To identify which incomplete block has to go, we look at the efficiency of each one.

The 334p is a healthy shape and could be completed by three tiles.

That means we’re looking at the remaining three shapes that could only be completed by one tile.

12s is the clear candidate to be cut here. It could be slightly upgraded with a 4s, but you’d still be left with a wait on one tile. Compare that with the other two where a good draw will upgrade it a two sided wait.

Next time…I’ll tackle the 6 Block theory!