I'm thinking of using TwinTrinkets to automatically swap out trinkets that have an on-use bonus when the on-use bonus is on cooldown. I understand that the relative benefits of a trinket rotation in specific situations (raid boss/trash, heroic boss/trash, 5v5 arena, etc.) hinge on (a) the amount of time spent in combat, and (b) the amount of time spent out of combat before re-engaging.

From what I've been able to plot out on a napkin, the maximum number of trinkets I can rotate through - assuming 2 minute cooldowns; both trinket slots used; and never swapping out a trinket that is ready to be activated, regardless of where it sits on the priority list - is either 6 or 7, depending on lag. Given the trinkets I have to work with (listed below), a perfect rotation appears to yield an additional 60 seconds of plus 140-280 attack power in the first 2 minutes 20 seconds.

Abacus of Violent Odds - 260 haste rating for 10 seconds, 2 minute cooldown
Core of Ar'kelos - 200 ap for 20 seconds, 2 minute cooldown
Ogre Mauler's Badge - 185 ap for 15 seconds, 2 minute cooldown
Bladefist's Breadth - 200 ap for 15 seconds, 1.5 minute cooldown
Ancient Draenei War Talisman - 200 ap for 15 seconds, 1.5 minute cooldown
Terokkar Tablet of Precision - 140 ap for 15 seconds, 1.5 minute cooldown
Earthstrike - 280 ap for 20 seconds, 2 minute cooldown

The downside of a rotation is that I will spend less time with my best two trinkets (in terms of total passive and active contribution to sustained dps, as modeled by pf in his rogue dps spreadsheet), and less activations of their on-use bonuses.

Unfortunately, this is as far as I've been able to take it myself. It seems intuative to me that trinkets with cooldowns should spend those cooldowns in my backpack, but I don't want to have a worse trinket equipped when a better one is available, and I don't have the math background to evaluate the risk-reward, establish break points, or even decide how many trinkets should be involved.

Is anyone able to take this farther?

The problem, of course, is that for a good portion of your +AP uptime, you are trying to get OUT of combat in order to be able to make the next swap, which means you are no using the additional AP bestowed by your trinkets, because hitting an opponent would prevent you from swapping the next trinket. Factor in the 30 second prep time and you have a series of self-defeating actions in your hands.

Chain-swapping would be more viable if trinkets can either
1)be swapped mid-combat
or
2)be swapped out of combat without the 30 second prep timer

Activated trinkets should not be worked into a rotation, but rather be swapped only when the opportunity arises. TrinketMenu has a trinket queueing feature that switches your currently equipped trinket with another in your inventory as soon as you are OoC.

Yes, Trinket Menu is invaluable for swapping trinkets. You can set a timer on trinket use so that as soon as the special for the trinket is up it queues the next trinket to be equipped.

Generally you'd only want to switch trinkets if you have more than 30 seconds left on the cooldown when you get OOC. I also don't see the usefulness in having more than your 4 best trinkets up at any time, since you want to pop 2 back to back then swap them out for your next best when combat is over.

Anyways, here's the cursed link. Hope it helps.
http://wow-en.curse-gaming.com/files...5/trinketmenu/

Same functionality is in ItemRack. During combat, queue up the trinket you want for the next pull.

On the whole, this is often more trouble than it's worth. It's right up there with "start with a high-Int weapon every pull, and swap to a high-damage weapon after 1-2 casts." It's really only worth doing when you're entrenched in a long trash clear that doesn't require you to focus on anything besides DPS for a while, and gives frequent combat breaks.

For example, I used to swap on the Razuvious trash. It was 20-25 mins with nothing better to do than try to top the meters. But even on the Shade of Aran trash or something, individual pulls are long enough that it probably won't work well.

The other thing to remember is that Mages have MQG on a 5-minute cooldown, which gives a huge amount of damage per-use. That can probably be worked in just about anywhere. But for other Mage trinkets, or for anyone who only has trinkets on a 90-120 sec cooldown, remember that you need to be breaking combat every 30-45 seconds or so for it to really work.

I guess the follow up question would be when can we reasonably expect to break combat in less than 45 seconds? 5v5 arena matches, maybe?

Solution: Trinketmenu
Number of trinkets: up to 4 / recomended 3 (2 swaping and 1 resident)
Works for rogue. On long fights you start fight, use trinket and he will que next one, than in middle fight you will use vanish anyway to drop some aggro so trinketmenu will swap it in that second that put's you OOC, than you wait 30 sec for that trinket CD so you can use 2 in same fight...

Not reliably for most classes. Hunters can FD, rogues can Vanish and/or gouge->restealth. Besides those, other classes are left with the option of farting around in the arena and actively avoid engagement.

With that said, I don't think hunters and rogues will blow their utility cooldown JUST to switch a trinket.

For trinkets, I think I agree that this may be more trouble than it's worth. The 30-second delay really hits you, even if you can drop combat at will. Before TBC I think someone did an analysis of hunter DPS using feign to swap trinkets and use them as fast as they could, and the gains were marginally better than using a good passive trinket.

But I disagree about swapping staves in combat. There you have no 30-second delay; as soon as you swap to a +damage weapon you get the perks. The biggest obstacles are remembering to do it, and dealing with the GCD it invokes. And there are mods that get around both of those:
http://www.wowinterface.com/download...onSwapper.html

Something like Hourglass or Dragonspine Trophy are going to be better than the 'use' trinkets for raiding really (except maybe the compas). When farming, the use trinkets are always going to be better, on average when killing elementals a fight takes ~20 seconds, with 10 seconds in between kills for looting and running to the next the value of these trinkets is immense since every other fight I get just about full use from them.

Or clearing trash in Karazhan. I can get up to 3 trinkets deep in my swapping as we chain pull our way from Curator to Aran.

Most of the groups last 40-60 seconds, and by the time the next set of mobs is on the way, my trinkets are swapping.

/startattack
/use [combat] Core of Ar'kelos
/use [combat] Ogre Mauler's Badge
/cast Sinister Strike

works fine for me. Are you sure you're not just bumping your head against the 15 second shared cooldown for activating on-use trinkets?