@@Jfto1222 It's a strategy called Mapless. I can't fully explain it here (you can look up a video if you want more info), but it's the reason he was looking around with the pie chart at the beginning
For people asking how he knew where everything was, at the start, he was waiting for an orange spike in the pie wheel at the center. The boat eye is a technique you can use which measures the angle of the eye and since one block in the nether= 8 blocks in the overworld, he goes back to the nether and using a coordinate calculator, he can know exactly where to build the portal. Hope this helps.
Some optimization mods like CaffeineMC, a couple for quick resetting like Atum, and SpeedrunIGT for the timer. MCSR has a website where you can download all the leaderboard-allowed mods if you want the full list.
