How to check if a Teiwaz has superior accuracy to Terra's Staff

Obviously, I am talking about the Teiwaz with elemental affinity: magic accuracy +3, not so much that I am talking about the earth-aligned Teiwaz.

It is thought that earth affinity: magic accuracy +1 is equivalent to the accuracy bonus of Earth Staff, and earth affinity: magic accuracy +2 equivalent to the accuracy bonus of Terra's Staff. If you ever read this blog, you would know that elemental NQ staves are considered to have +20 magic accuracy for the specified element, and HQ staves, +30 magic accuracy. It is postulated that elemental affinity: magic accuracy +3 corresponds to +40 magic accuracy.

Without discussing the evidence underlying the following experiment to check whether the earth Teiwaz is superior to Terra's Staff, I will describe a superiority "trial" involving relatively few casts.

Location: Alzadaal Undersea Ruins (Nyzul Isle Staging Point)
Target monster: Level 78 Qiqirn Poulterer (ranger)
Spell to cast: Stone (I)
How many casts: 100.
What to count: number of non-resisted Stone I, number of half-resisted Stone I, number of quarter-resisted Stone I, number of eighth-resisted Stone I (should be easy to identify from the magnitude of damage)

How to identify the level 78 Qiqirn Poulterer: one way to check you have found the correct level Qiqirn is to set your accuracy score to 263 and use the "check" function to find the right Qiqirn. One way to achieve this is to equip a weapon type for which you have 230 combat skill (example: BLM with max club skill). 230 combat skill corresponds to 227 accuracy. Suppose you also have 62 DEX. For a one-handed weapon (club), this means you have +31 accuracy. Then equip +5 accuracy worth of equipment (example: Chivalrous Chain) to achieve a total accuracy score of 263. Level 77 and 76 Poulterers will check "low evasion," while the level 78 Poulterer will give no evasion message. Incidentally, this implies the level 78 Poulterer has at least 293 total evasion. You can confirm the level after killing the Poulterer by noting EXP yield (200 base EXP for level 78, 230 given 15% Sanction bonus).

Total magic accuracy for this experiment: it is known reasonably well (I will not cite evidence at this time) that having 65 INT, 290 elemental magic skill, +5 magic accuracy (from equipment), and no elemental staff corresponds to having about 55% magic accuracy rate for the Stone I spell. (The level 78 Qiqirn Poulterer has 65 INT.) If your elemental magic skill is higher or lower (say 292), make the appropriate adjustments to INT and/or magic accuracy. Here, +/-1 INT is considered +/-1% magic accuracy rate (up to a point), and +/-1 magic accuracy (from equipment) is considered +/-1% magic accuracy rate, too.

Given the above, equipping a HQ staff like Terra's brings your magic accuracy up to ~85%. A "quickie" trial I ran gave 57/71 non-resisted Stone I, strong evidence of uncapped magic accuracy rate. As postulated previously, equipping a Teiwaz with earth affinity: magic accuracy +3 could bring your magic accuracy up to ~95% (the maximum rate).

Why 100 casts of Stone I on a level 78 Qiqirn Poulterer? 100 is an arbitrary figure as I am too lazy to do a power calculation, but since we know a priori that Terra's Staff doesn't even give a capped magic accuracy rate (and it shouldn't since I said it would be ~85%), it will be very easy to show that, if the Teiwaz earth affinity: magic accuracy +3 really has +40 magic accuracy, the observed data will indicate a capped magic accuracy rate. Of course, if the accuracy bonus were higher than +40, this test wouldn't be able to show that, but the in-game constraints described by the current magic accuracy "model" and a desire for a "minimal" sample size (the further away from 50%, the smaller the standard error) led to the above experimental conditions.

Considerations: avoid Qiqirn Goldsmith links. To minimize damage from ranged attacks, it is preferable to be RDM. If not, have someone spam heal you while you hammer out 100 casts in short order. It really doesn't take that long.

Questions and desired clarifications about experimental conditions may be fielded in the comments, if anyone actually gives a shit.

Credit to pchan on BG for previous work on Qiqirn Poulterers that allows for a fairly straightforward and not-onerous experiment.