The difference affecting the speedruns the most is that in the Red version you can catch Nidoran♂ on Route 22 (in the Blue version it's Nidoran♀ instead). This is very important because using Nidoking is the main strat used by all top runners of this game. This is the only version difference which affects the run at all, because no one has found the faster route so far.
But running Pokémon games is much more complex than just going with a chosen route. Having knowledge about all the battles, including those you can avoid but you cannot always do that (although in this gen spinners are not a thing), as well as rng mechanism and adapting to different situations, play a huge part of it.
@mistryzoda123 You can get Nidoran Male in blue as well, and there’s even an RNG Manip for it. The version differences is how the RNG advances which causes the manips to be different and the Blue Version has slower resets due to Squirtle having a longer cry than Charmander. The routes are near identical other than the manipulations being being done with different inputs. There’s just not one consolidated place where the route for Blue has been documented.
