@tx3000, your chance to hit is the number which you see right next to the attack symbol. In one case it is 46 %, in the other case it is 31 %. The chance to hit is defined as the successful chance to hit a particular enemy in a particular situation: it depends on your offence rating, your dexterity, the distance and the enemy's defence rating. What is fixed by the dexterity is your offence rating which you can see in the character's sheet. It is not possible to calculate the abstract chance to hit without knowing the enemy's defence rating, the distance etc.
Btw, armour is irrelevant for the chance to hit. It is only relevant for the damage reduction if the enemy is actually hit. Defence rating is the one number which is responsible for dodging of attacks.
