From a thf player guide on wiki:
http://wiki.ffxiclopedia.org/wiki/Th...laying_the_Job
I do stack some STR on my thf for added attack, btw.
Stats That Should Be ObtainedEdit
Agility - AGI does a lot of things for Thief. One of the big things it does is powers Trick Attack (Job ability obtained at level 30). Each point of AGI adds 1 to your weapon damage for the Trick Attack hit. It also improves your evasion, parry, shield, and ranged accuracy stats. It's good if you have your Pulling macro that equips all of your AGI+ gear before you Ranged Attack it. It will help for the best results of you actually hitting the monster you are pulling and it will give you extra Evasion as you run back to your party. For every two points of Agility a character has, these stats are raised by one point.
Dexterity - DEX also does quite a few things, one of the most important thing is that it powers Sneak Attack (Job ability obtained at level 15). Each point of DEX adds 1 to your weapon damage for the Sneak attack hit. It is said that each point of Dexterity raises critical hit rate by 0.125%. Dexterity also has a direct impact on a character's accuracy stat. For every two points of DEX a character has, his/her accuracy is raised by one point. DEX is also the driving factor in almost every THF weapon skill.
Strength - STR is generally avoided by Thieves. Because Thief has naturally low Strength, overcoming an enemies' Vitality and thus raising the STR variable is more difficult for them than other jobs. In addition, all of Thief's weapon skills use mostly DEX mods, especially Shark Bite at 66, which has a 50_%DEX mod attached to it. Because of this, DEX generally adds more damage to weapon skills than Strength will. However, strength can also raise your Attack, which is beneficial. Strength also raises your Ranged Attack, so gaining Strength and Agility for Ranger isn't such a bad idea. Every two points of Strength raises your characters Attack and Ranged Attack by 1 point.