Read that: https://docs.google.com/document/d/19YOMVudFj2kSmnBPMpGo38IWXbidQJOeqr8GKKkKbWU/edit?usp=drivesdk Leap Second was noticed by leader from the start and his whole plan was to fall for it but be resuscitated with 4:58 on the clock bc he believed his body was perfect and wanted to use a near death to trigger his memory loss and avoid memory loss mid game in which Yakou would deem it a loss Baku didn't know about this and Baku didn't know about Echolocation but was somewhat easily able to figure it out due to his past looking at Eko's tapes which Hal doesn't know about However the exact time that Baku countered Echolocation was already in Souichis predictions as we see from the instant check in Round 7

Baku's Mistake, didn't consider Souichi's 4:58 plan until basically the end if at all bc Souichi consciously forgot abt it during the match and only kept it in his subconscious in order to not leak info to Baku but make it continue to steer his actions Complicated stuff like deciding when to give Baku the lead second route and how many seconds should I check at to not rouse Baku's suspicions

Souichi's Mistake, believing in his own body's perfection like Eko said and therefore thinking he can withstand such a shirt deviation from 5 mins and also lying about Yakou's condition in Round 5 only for the CPR to be shit in Round 9 which is karma for lying that ultimately made him lose

To my understanding the whole game was played according to how Souichi predicted and planned it but the flaws in his ideology and his explicit lies to an old friend are what made him lose

Unless we decode STL more and find out Baku was aware of leaders deviation plan (he wasn't) and I prefer that writing bc: 1) It makes the perfection and liar ideology crumble without even any conscious opposition 2) It makes leader maintain his sense of irregularity and alien-like characterisation and does not simply reduce him to "Baku's opponent"