Shadow of Doubt as a serious sideboard card?

[Harlequin]

It might be good for U/R fish, or Mono-blue, but heres the simple truth...
UB Fish and UB decks in general run alot of its threats in sorceries, duress comes first to mind.  But in general UB fish RARELY can afford to sit on 2 colored mana for turn after turn, on the hope that your opponent is going to play a tutor.  Shadow of Doubt doesnt fit the mana tempo of UB fish.  The builds of UB fish almost all run FOW, Daze and if they run any other countermagic is all 1 mana stuff (annul or disrupt)  They never leave more than 1 mana open at the end of 2nd main.  Your crippling yourself by sitting on 2 mana turn after turn, why not just duress the tutor and be done with it. 
I would say if your already running 4 FOW, 4 durres, 3-4 daze and 2-3 Cabal Therapy AND you think to yourself "hrmm I think this deck could use a bit more control... " Then go ahead and add SoD, but you better be running Battle of witts too
 

What is intresting about the card is that you can play it in any heavy control, and it can be played in tog (wich is needless to say, not fish).  This I could see.

[Buttons]

I think you have a point, but in UB fish, who's going to expect SoD?

The BU build that's going on in the current post has EIGHT duress effects - 4 Mesmeric Fiend and 4 Duress.

It runs 4 FoW and no anything else.  2 SoD is a fine addition there.  It's pointless against UbaStax, of course, but UbaStax will own any kind of Fish no matter what, so it's tapering more to the Oath and Gifts matchups (which it has AMAZING results against, might I add).

Go check out the build, I really like what the guy did with it, and I added in some suggestions.

You have a great point with the sitting on mana, however.  The thing is, tutors become really prevalant not in the immediate game, but in the early-mid and mid games, where SoD can REALLY come in handy.

[fromm2020]

i played the card at chicago and i wishes i played more rebs or pyroblast, it hinders gifts for like 1 turn when they still have other tutors to use, and if ur worried about grimlong then just play more counters, plus you cant shadow will,bargain,potence, or any other decent combo pieces

[rakso]

So... did Shadow do anything decent over the last month?

After Chicago, I didn't hear anything else about this card.

[Kieranwolf]

I've played blue control for around a half-year, now, and personally I think that Shadow of Doubt simply doesn't belong in there. Max brought up the point that tutors can get uncounterable things, sure, but no control deck survives without either having other answers to the tutored cards, or being able to play around or outrace them.

This is one reason why I favor strip effects and board control. These are things that blue decks have easy access to, because of the ease of incorporating other colors into the mix. Many blue decks, though, just try to be literally too fast to hate, like Hulk and Combo. I have tried both strategies, and indeed many decks are quite capable of both, and thus probably don't need a card like this.

However, I do run SoD in my non-blue Loam Aggro deck. Why? It answers Tinker. It's as simple as that. I needed a way to NOT get my face smashed by Colossus or a lesser robot, and Diabolic Edict wasn't enough on its own (consider Pentavus). Black has enough disruption to kill any useful cards in its opponents hand, but cards like Duress, Mind Twist, Cabal Therapy, and Hymn to Tourach are sorceries. Disruption (excepting maybe Necrogen Spellbomb against an empty-handed opponent) does not answer a top-decked Tinker or Gifts (both excellent ways for a blue deck to come back for the win).

SoD is not often the most optimal card for Fish or any deck that needs to abuse tempo. Sure, it's a cantrip, but it still costs two colored mana. In an aggro deck, it requires leaving mana open, thus keeping a threat off the table for the player holding it for another turn. However, the card is essential for Loam Aggro's matchup against decks that run Tinker. SoD can be as fast as an early Gifts or even an Intuition at times, but in a blue deck with dual lands, it's not as good as Drain (or even Force of Will). Stifle, too, is a better answer to not just fetches etc. but any activated or triggered ability.

SoD may often be a consideration for many decks because of its versatility, but I would only seriously run it in a non-blue deck. Blue just has better answers, even though no other single card does quite as much by itself. Black has few or no hard counters to cards like Tinker and Gifts, so SoD can (and has been) gold for it.