And I've been playing for most of them. I started gaming in 1977 and first played D&D when I got to college two years later. I still have my AD&D books and have been rediscovering them through my soloplay campaign. I'm struck by how much we ended up ignoring, encounter distance, encumbrance etc. To be fair we did use the grappling rules which didn't get fixed until Pathfinder - or 3.75e as my group calls it. I'm also struck by the disorganized strucure of the Players Handbook and Dungeon Master's Guide. It's not easy finding the rules in there, take Encounters, the rules start onpage 47 with encounter frequency and distance, then hare off on Movement and Getting Lost, make stops at Infravision & Ultravision, Invisibilty, Mirrors and Listening at Doors before you get to Surprise onpage 61, then Initative, finally getting Encounter Reactions on page 63. Who cares about their reaction, I'm combat at this point.
Does the O in OSR stand for Obfuscatory?