Arms plays a priority list built on short cooldowns. You spend the fight in Battle Stance, keeping Rend up so that Overpower keeps opening, and move to Berserker Stance once for the Execute phase. Rage decides how far down the list you get.

Before the pull

• Bloodrage goes first, 8 to 15 seconds out depending on the fight, so you pull with rage in the bar and its one-minute cooldown is already running. The pre-pull Bloodrage is worth 0.0 %.
• Battle Stance at 10 seconds. Rend, Overpower and Spearing Strike all need it, and the sim's warrior would otherwise start in Berserker Stance. That makes this one swap worth 17.0 %, more than most lines in combat.
• Battle Shout just before the pull, so its three minutes cover the whole fight.

Priority

Read the list from the top: whenever you can act, use the first line that is ready. It is not a fixed sequence.

In words:

1. Swap to Berserker Stance when the boss reaches 20 %. You gain 3 % crit and the stance Recklessness needs, and you lose nothing Execute uses. The swap is worth 4.4 %.
2. Execute below 20 %, whenever it's ready. Each one is 600 damage plus 15 per rage point beyond its cost, and it empties your bar. From here to the end you press little else. It is worth 7.2 %.
3. Rend when it has under half a second left. Rend itself is only 4.3 % of your damage, but Bloodthrill needs your Rend on the boss to open Overpower. That is why the line is worth 12.6 %.
4. Overpower whenever you can. It can't be dodged, costs 5 rage and crits 85.8 % of the time. It is worth 14.8 %.
5. Slam when it's off cooldown. With Improved Slam the cast is short and doesn't stop your swings, so it costs only a global cooldown and 15 rage. Worth 3.6 %.
6. Mortal Strike on cooldown. Your biggest regular hit, every 6 seconds, and the clock the Hamstring line runs on. Worth 20.5 %.
7. Spearing Strike on cooldown. 15 rage every 20 seconds, in Battle Stance only, worth 3.4 % against the Dragonkin boss we simulate.
8. Hamstring when Mortal Strike is a second or more from ready and you have rage to spare (over 20, or 30 on one minute). It deals little, but it is a main-hand hit, so each one is another 20 % roll for an Overpower window, and its crits feed Deep Wounds. That makes it worth 4.2 %, at about 8.8 a minute.
9. Bloodrage below 85 rage. It's off the global cooldown.

More than one target

Bring Sweeping Strikes in as soon as a second boss is in reach. For 30 rage it makes your next five melee attacks strike another enemy too, and it only works in Battle Stance. On a three-minute fight against three bosses its copies are 12.1 % of your damage. Add Cleave below Spearing Strike at 80 rage or more and during Execute. The rest of the list doesn't move.

The search changes the build as the three-boss fight gets shorter. On two minutes, with pre-raid gear, it leaves Mortal Strike out and spends the rage on Cleave. On one minute it plays Whirlwind from Berserker Stance and steps into Battle Stance only for Overpower. There Whirlwind is 22.5 % of your damage and Cleave 24.0 %.

Cooldowns

Recklessness has a 30-minute cooldown, so you get it once.

It needs Berserker Stance, so it waits for the Execute phase. The sims press it about 20 seconds before the end on two and three minutes, and as Execute starts on one minute. That puts its 100 % crit on your Executes: on three minutes Execute crits 64.9 % of the time against 34.0 % for Mortal Strike.

Blood Fury (Orc), Elune's Light (Night Elf), the Mighty Rage Potion and the Goblin Sapper Charge go out at the pull, and Blood Fury and the potion again two minutes later if the fight lasts.

The potion's 60 rage and 60 Strength are worth 4.2 % on this fight.

Real bosses don't die on a timer. Time the end-of-fight cooldowns to the boss's health rather than the clock, and if your raid kills faster than our fights last, press Recklessness early enough that none of its 15 seconds goes unused.

Cooldown	Uses	At
Bloodrage	2	0:00, 0:52
Elune's Light	1	0:00
Mighty Rage Potion	1	0:00
Goblin Sapper Charge	1	0:00
Recklessness	1	0:49

What your log should show

Compare your Warcraft Logs report with the table below. Fewer casts a minute than these means lost global cooldowns. A short Overpower count usually means Rend fell off.

Ability	Casts per minute	Of damage	Crit
Auto attack	19.0	23.5 %	41.8 %
Execute	5.6	15.4 %	99.8 %
Overpower	7.0	15.2 %	85.8 %
Auto attack via Windfury Totem attack	10.0	13.4 %	41.6 %
Mortal Strike	7.5	13.1 %	35.9 %
Slam	3.0	4.7 %	35.8 %
Rend	3.1	4.3 %	40.6 %
Spearing Strike	2.4	4.1 %	36.8 %
Deep Wound	30.3	3.9 %	0.0 %
Goblin Sapper Charge	1.0	1.2 %	20.2 %
Hamstring	8.8	0.9 %	36.4 %
Dragonbreath Chili	–	0.4 %	28.6 %
Mighty Rage Potion	1.0	–	–
Battle Shout	1.0	–	–
Battle Stance	1.0	–	–
Elune's Light	1.0	–	–
Bloodrage	2.0	–	–
Berserker Stance	1.0	–	–
Recklessness	1.0	–	–

The numbers to compare: about 7.5 Mortal Strikes and 7.0 Overpowers a minute, and Execute at roughly 15.4 % of the total. Windfury Totem's extra attacks are logged as a separate auto-attack line, here 13.4 % of the total.

Uptimes

Buff or debuff	Uptime	Times per fight
Battle Shout	100.0 %	2.0
Windfury Totem aura	100.0 %	13
Rendon the boss	98.2 %	3.0
Deep Woundon the boss	97.5 %	30
Battle Stance	80.3 %	1.0
Overpower	54.0 %	15
Holy Strength	53.9 %	3.5
Mighty Rage Potion	33.3 %	1.0
Elune's Light	25.0 %	1.0
Berserker Stance	19.7 %	2.0
Recklessness	18.9 %	1.0
Windfury Totem	9.6 %	10.0

Rend matters most here: it should be up about 98.2 % of the fight. It drops off once you leave Battle Stance at 20 %, which is expected. The Overpower window, listed as Overpower, should be open about 54.0 % of the fight.