Minecraft wiki entry for Mining, associated text: A 2×1 shaft is probably the highest-yielding way of mining for ores that is. Mathematically, a 2×1 shaft reveals 8 blocks for every 2 blocks mined forward, so the basic premise of this system is that digging little 10-block deep side shafts off of their main tunnel, as in branch mining, does not yield any more ores than digging straight as their yield will be highest if they simply keep moving forward and mine endlessly instead of stopping a 2×1 shaft will also lead them into plenty of caves, which could be good or bad depending on how they have feel about those. A good strategy for cave run-ins is to make a quick run-down and nab any visible ores, then find their shaft and keep moving. If they don't want to walk all the way back home after digging this, just dig in a "U" shape until a little less than half of their pick is used up, move 8 blocks to the side, and go back. The 2 biggest problems with this kind of mining are: A. It takes a lot of torches, though their coal yield is way higher than the amount they have spend on torches, and B. They have covered a lot of distance, therefore their chances of having lava run-ins are pretty high.