Stronghold Triangulation
MediumNavigationThrow two eyes of ender a short distance apart, measure both angles and work out where the lines cross, instead of following eye after eye. Since November 2021 speedrun.com has allowed tools that read the angles and do the math, and the Java rules name Ninjabrain Bot as allowed.
When to Use
Whenever you need a stronghold in a random seed: right after the fortress in Any%, or before Nether travel toward it. In set-seed runs you already know where it is.
Estimated Time Save
Following eyes one throw at a time
Step-by-Step Guide
Stop completely
Stand still before you throw. Your F3 coordinates can look stationary while the game still has you moving, and that ruins the angle. Pushing into a corner between two blocks stops you quickly.
Throw and measure
An eye flies about 12 blocks toward the stronghold's starting staircase, hangs in the air for a moment and then drops or shatters. Look straight at it and read the horizontal facing angle on F3, or press F3+C so Ninjabrain Bot records the throw.
Move sideways
Walk 17.5 blocks at a right angle to the eye's path, stop again and throw a second eye. Measure it the same way.
Work out the distance
Subtract one angle from the other. 1,000 divided by that difference in degrees is roughly the distance in blocks, so a 2 degree difference means about 500 blocks. Ninjabrain Bot skips the arithmetic: it models your measuring error and where strongholds can generate, and gives coordinates for the most likely chunk.
Travel
Far away and carrying obsidian: divide the distance by 8 and travel in the Nether. Under about 600 blocks, walking in the Overworld is fine.
Dig down
Within 12 blocks of the northwest corner of the staircase chunk, a thrown eye flies down instead of up. Strongholds generate at any height and can even cut into bedrock, so dig carefully.
Fill the portal
The portal room has 12 frames. Each has a 10% chance to hold an eye already, 1.2 on average, so count the empty frames before you start placing.
Pros
- +Two throws can replace a long chain of single throws
- +Gives you a spot to dig, not just a direction
- +Ninjabrain Bot is allowed on speedrun.com and accounts for measuring error instead of trusting a perfect line
- +Works with plain arithmetic when you have no tool open
Cons
- -Each throw has a 20% chance to shatter the eye
- -Small angle errors grow into big position errors at long range
- -Moving during a throw can spoil the reading without you noticing
- -Runs that use F3 must be marked as F3 runs and show the F3 screen on video