After the release of the AD&D game, the Basic Set saw a major revision in 1981 by editor Tom Moldvay. The game was not brought in line with AD&D but instead further away from that ruleset, and thus the basic D&D game became a separate and distinct product from TSR’s flagship game AD&D. The former was promoted as a continuation of the tone of original D&D, while AD&D was an advancement of the mechanics.
I have a personal preference towards AD&D and its wider ranger of options, but from the objective standpoint Moldvay's Basic/Expert line really is far superior, and I'd be hard-pressed to imagine a better system to begin your roleplaying hobby on. The rules are simple, the system is focused, it's easy to read and get into, and the adventure modules written for it still withstand the test of time.
Recovered a huge stash of 1980s era Dungeons & Dragons material in my parent's attic last December. This is the first item of what will likely be a multi-year reread. Fun and nostalgic- plus interesting to see how the game has evolved.
A fairly short rulebook that's absolutely the most full version of the Basic game yet. It feels much more thought through, but still feels to be in the lineage of the original game