Damage vs Accuracy

[Gordon]

Dropping down to dlvl 75, I ended up in a small rectangular room. Casting my usual mae, mdf and mcg, I saw no traps, no monsters and only one unknown item in the room. I sauntered over to take a look and saw a Mithril ring. At this point there were only 5 unknown rings, 4 of power and Tulkas. A Mithril ring sure sounded like...yes! Nenya! I can't believe I found it without having to fight my way through a horde of Pit Fiends. Now I can get rid of this shabby looking Hard Leather Cap of Thranduil and finally wear this beautiful Golden Crown of Gondor that I've been hauling around to occasionally protect me from confusion and stunning. I can also lose the Ring of Constitution <+6> that I have been wearing forever, it seems. And my Ring of Speed <+12> is pretty much redundant at this point. Not much difference between speed 34 hasted and speed 46 as far as I can see. This opens up a ring slot and hence my question.

I have two candidate rings, a Ring of Accuracy (+21,0) and a Ring of Damage (0,+15). I see that accuracy is dismissed a lot here, but looking in my monster memory at the Great Wyrm of Chaos, for instance, I see that by wielding the Ring of Accuracy, my chance to hit rises from 35% to 47%. When wielding the Ring of Damage, my sword does 348 damage per round against evil creatures. Multiplying this by 0.35 yields effective damage per round of 121.8. Meanwhile, wielding the Ring of Accuracy gives 292 damage per round. Multiplying by 0.47 yields 137.2 effective damage. The Ring of Accuracy has the additional benefit of fewer wasted shots when I use my bow. So how is it not advantageous to choose the Ring of Accuracy over the Ring of Damage?