Straight up: the thief sucks in B/X D&D. It's the only class that is actually bad at its core shtick.
But we can fix that. Above you see the rather baroque and over-complicated division of thief ability scores and their chance of success per level. My advice: just use the Hear Noise column for all Activities Thiefly in Nature.
This also means that you can assign a 1 in 6 chance of success to non-thieves trying to do Thiefly Stuff.
Sorted.
(This was an old idea I had from years ago that someone asked to see again, so here it is, posted for posterity.)
