Announcing (or not announcing) triggers :Sabertooth Outrider

[LotusHead]

My opponent at FNM attacks with their team, and he definitely has Formidable.
A bystander says there was a missed trigger and thinks that the Outrider will NOT have first strike, whereas I think that the Outrider automatically has first strike, unless the controlling player actually forgets and does normal damage instead of first strike damage.

Does my opponent have to say his guy has first strike when it triggers, or can he just say 4 damage first strike during the damage dealing step (ie demonstrate awareness that his guy has first strike when its damage dealing time?)

Our local judge got conflicting answers, and as this scenario is very similar to that Chalice of the Void situation with me vs TheAtogLord last year, I really wanna know where the rules currently stand on this.

Thanks in advance!

[H]

Since the trigger has no visual game state implications (like placing counters on something, or making tokens, etc.), I am pretty sure he only needs to acknowledge it in the First Strike combat phase to not have missed it, which is the first time the trigger would have an impact on the game.

A triggered ability that affects the game state in non-visible ways: The controller must take physical action or make it clear what the action is by the first time the change has an effect on the visible game state.

Not a judge though, so someone may correct me, but I think this is correct, but I don't know of your Chalice situation, so maybe I am missing what you are saying.

[The Atog Lord]

Yes. The opponent need not acknowledge this trigger until it is time for damage.

[ELD]

How does this interact with Stifle?

[LotusHead]

but I don't know of your Chalice situation, so maybe I am missing what you are saying.

http://www.themanadrain.com/index.php?topic=45533.0
Link to tourney report is in opening post.

[H]

How does this interact with Stifle?

We're beyond what limited rules knowledge I have, so I'd have to let an actual judge field this.  My best understanding would be that the Stifle player is actually at something of a disadvantage, in the sense that they would have to acknowledge the trigger first.

but I don't know of your Chalice situation, so maybe I am missing what you are saying.

http://www.themanadrain.com/index.php?topic=45533.0
Link to tourney report is in opening post.

Sorry, I didn't see it.  Thing is, yes, the rules as currently constructed allow you to gain some advantage by not immediately announcing your triggers.  The rule is not perfect, but it's what we have.

[Chubby Rain]

How does this interact with Stifle?

This article, although long, does a good job of going through the nuances of missed triggers. It is a Wiki page, so it may not be entirely accurate, and it does not explicitly mention Stifle in this context. It would definitely be helpful to have Clariax chime in.

http://wiki.magicjudges.org/en/w/Annotated_IPG/Missed_Trigger

The relevant blurb for Stifle and triggered abilities appears to be:

If an opponent requires information about the precise timing of a triggered ability or needs details about a game object that may be affected by a resolved triggered ability, that player may need to acknowledge that ability’s existence before its controller does....as the IPG says, “triggered abilities are assumed to be remembered until otherwise indicated.” The example they give is Shocking an Exalted Grizzly Bear.

My interpretation of this is you have announce you are Stifling the ability when it would be resolving according to game rules, even though it gives the Stifle player somewhat of a disadvantage (aka I agree with H).

[LotusHead]

I would still like a judge (Clariax!) to rule on this. You know...for posterity.

[Clariax]

Everything here is correct.  If you want to Stifle it, you need to do it while it's on the stack.  You can't wait until multiple steps after it resolves until you know your opponent remembered it to retroactively stifle it.