I gathered some warrior stat informations:
Base values:
A lvl 85 Warrior has:
3.758% base doge
5% base parry
5% base block
Ratings:
1 point in mastery per 179.28 mastery rating
1% dodge for 176.71899 dodge rating (without dimishing returns)
1% parry for 176.71899 parry rating (without dimishing returns)
1% block for 88.36 block rating
Strength/Agility conversion:
A lvl 85 warrior will get:
1% dodge per 430.69 agility
25% of strength will add to parry rating (and thus mitigated by dimishing returns)
Example: If you have 2759 strength that will convert into 2759 / 4 = 689.75 parry rating that will be added to the rest of your parry rating.
That is why casting Battle Shout will increase both your chance to parry and your chance to dodge.
Block example:
The sentinel talent will give 15% chance to block.
The mastery talent will give 12% chance to block and 12% chance to block critically.
One point in mastery will add 1.5% chance to block and 1.5% chance to critical block.
If you have 2000 mastery rating those will convert to 2000 / 179.28 = 11.155734 mastery points.
11.155734 * 1.5 = 16.733601% chance to block.
Thus a lvl 85 warrior with 2000 mastery rating will have
5% (base block) + 15% (sentinel) + 12% (mastery talent) + 16.733601% (mastery points) =
5 + 15 + 12 + 16.733601 = 48.733601% chance to block
Dodge example:
119 base agility
139 agility from gear
549 agility from battle shout
(119 + 139 + 549) / 430.69 = 1.87373749% chance to dodge from agilty
1500 dodge rating on gear
1500 / 176.71899 = 8.48805213% chance to doge from doge rating (without dimishing returns)
3.758% (base doge) + 1.87373749% (agility) + 8.48805213% (dodge rating) =
8.48805213 + 1.87373749 + 3.75800 = 14.1197896% chance to dodge
Because of dimishing returns the actual dodge will be slightly below that value.
Parry example:
194 base strength
2750 strength from gear
549 strength from battle shout
(194 + 2 750 + 549) * 0.25 = 873.25 parry rating from strength added to your parry rating on gear.
700 parry rating on gear
873.25 + 700 = 1573.25 parry rating including parry rating from strength
1573.25 / 176.71899 = 8.90255201% chance to parry from parr rating (without dimishing returns)
5% (base parry) + 8.90255201% (parry rating) =
5 + 8.90255201 = 13.902552% chance to parry
Because of dimishing returns the actual parry will be slightly below that value.
Battle Shout has double usage now. It buffs our damage and our tank stats and should not be overlooked. It will grant both dodge and parry.
The strength/parry conversion is the reason why your parry rating gets skyrocketed once you reach t11 gear level. Even more strength and even more parry rating will push your parry rating even further.
Sources:
Combat Ratings at level 85 (Cataclysm)
chardev 8 - Cataclysm Beta