Critical hit rate bonus of Fencer

(Edit: now with information on Fencer with dual wield.)

Fencer is a new job trait from the July 21, 2010 version update that is available to the Warrior job at level 45 and the Beastmaster job at level 80. It has the following help description: "Increases rate of critical hits when wielding with the main hand only. Grants a TP bonus to weapon skills." The critical hit rate bonus was estimated using the following procedure.

Methods (brief)

An estimate of the critical hit rate bonus was obtained by auto-attacking overnight a level 69 Ul'hpemde, which has AGI 65 (source). WAR75/MNK01 was used. The following equipment was used to obtain STR 57, DEX 64, and an accuracy score of 276:

• Trainee Knife (240 dagger skill)
  
• Walahra Turban
• Dusk Gloves
• Snow Ring (STR -2)
  
• Swift Belt (Accuracy +3)
  
• Aurum Sabatons (DEX +3, accuracy +5)
  

STR 57 ensures 0 damage to any Ul'hpemde, and DEX 64 ensures (with 4/4 critical hit rate merits) a 9% critical hit rate before the effect of Fencer (source). kparser was used for automated data collection.

The level of the targeted Ul'hpemde was inferred by comparing the predicted hit rate for a level 69 Ul'hpemde (.92) against a point estimate of the hit rate of 5628/6133 = .9176 , with 95% confidence interval (.9105, .9244). The observed hit rate is consistent with the prediction.

Estimation of Fencer's effect with dual wield was also done with a Trainee Knife/Trainee's Needle combination, but the Ul'hpemde was level 68. (Critical hit rate is "directly" independent of level, but not AGI, which depends on level to some extent. But for both level 67 and level 68 Ul'hpemdes, the AGI is 65.) The following image summarizes the final base attribute values for this particular trial:

Results

Single wield: A point estimate of 802/5628 - .09 = .0525 was obtained for the critical hit rate bonus, with a 95% confidence interval (.0434, .0619).

Dual wield: A point of estimate of 464/4983 - .09 = .0031 was obtained for the critical hit rate bonus, with a 95% confidence interval (-.0048, .0115).

Interpretation and conclusion

Since critical hit rate has statistically been shown to take only integer percent values, assuming that the bonus is additive, the critical hit rate bonus of Fencer is either 5% or 6% with 95% confidence.

For the dual-wield case, suppose there were a 5% bonus for the main hand and none for the off hand. The effective bonus would then be 2.5%. Yet the observed estimate is much less than 2.5%, which should be taken as evidence that Fencer has no effect when dual wielding.