Let's take the more general case: no Reno opponent.
As Miracle, you are going kinda slow. So, if you pop this card early enough, you're likely to get at least 1x 4/4 during the match. And you paid (3) for it, so it's ok. Good with Preparation, especially for Edwin drops.
Against Reno, you have to add the vital part where Reno is actually shut down. Possibly Kazakus too. It becomes a win condition.
The worst case is when you could have used something else instead, ie a good taunt against Aggro. But Miracle rogues don't particularly tech against Aggro anyway, so I can't see any card being a superior tech in the current meta where pretty much 3/9 classes (3/7 if you remove Hunter and Pally from the count) use Reno.
No offense, but almost everything you wrote is wrong:
1. Miracle isn't slow, at least not the current variants. With the pirate package, it's very easy to kill opponents before you even get to the auctioneer. And even if you get to the auctioneer, you try to assemble your combo as fast as possible, you don't rely at all on long-term value.
2. Paying 3 mana for a 4/4 several turns later is absolutely not okay. It's atrociously bad. If there was a card that read "3 mana: get a 4/4 3 turns later" nobody would use it because it's way too slow. And beneath the ground is even worse tempo-wise than that because you'll get the 4/4 even later on average.
3. Everything else with prep is better than BtG for Edwin. Eviscerate, Knives, Sap, etc., all these things allow you to kill/remove enemy minions , which is the most important thing for you against aggro and midrange. Knives f.e. even refills your hand, which is important against control because you want to cycle through your deck as fast as possible.
4. While we're at aggro: No, you don't play defensively against aggro like using taunts or heals. You try to remove his minions and kill him before he kills you, that's your "tech" against aggro. BtG doesn't help you with that at all. This means that against aggro, your "worst case" is actually the average case.
5. Even against control, your win condition is assembling a big combo finisher. Thus, everything that doesn't draw cards or is part of such a finisher is detrimental for your game plan. BtG does neither. BtG only gives decent value long after you should already have assembled your combo.
The only thing you're right about is that it shuts Reno down. The problem is, Reno himself shouldn't be of much concern for you with Miracle since you should be able to easily deal 20+ damage with your combo. Ice Block is actually a much bigger hindrance.
BtG only really makes sense in control and/or mill because control likes the great value and shutting down Kazakus is important in this matchup, while mill can draw into BtG much more reliably, but neither is viable for rogue.
The only Reno rogue has to fear is Mage, and not because of the Reno'zakus duo. Example: Miracle Rogue has an edge against Renolock, and they also run those cards too. Mage has better big target removal, has stronger and non-self inflicting AOE damage,... And even if removal isn't available yet, has always the option to freeze to delay another turn. Ice Block not only denies lethal, but can also deny tons of burst damage if activated at wrong time.
Even Leeroy combo Renolocks are in big trouble versus Mage, they can't deliver the massive killer blow that easily.
BTG is the god of bad aggro players scapegoating Reno for their failure. Yes, because I defeated many pirate warriors because they went full face with weapons, leaving a minion alive on board that secured two turns of vital trading, or, at least, something to make a Defender of Argus or a Sunfury Protector valid plays.
A few days I played an Aggro Shaman vs Aggro Warrior, got full 9 damage from Spirit Claws 3 turns in a row, not because I was lucky with hero power, but because Bloodmage Thalnos lived 4 turns... And if you ask him what went wrong, probably was because of Reno+Kazakus too.
But the point is, either Reno is a serious threat for Miracle - in which case no card has more overall value than Beneath the Grounds - or it is not, in which case I wonder why the whole thread was opened.
Gang Up on Weasel Tunneler should be a suitable replacement for BTG :p
Do you think my Drain mechanic might be able to beat Reno decks? It's a keyword I invented for a class called The Soulmancer.
Vote for my Soulmancer class in Class Design Competition #3
Considering the last two times I played it the Renolock drawed all three the next turn, and the mage drew two of of them on his turn.
@linvega2 nailed it.
The only Reno rogue has to fear is Mage, and not because of the Reno'zakus duo. Example: Miracle Rogue has an edge against Renolock, and they also run those cards too. Mage has better big target removal, has stronger and non-self inflicting AOE damage,... And even if removal isn't available yet, has always the option to freeze to delay another turn. Ice Block not only denies lethal, but can also deny tons of burst damage if activated at wrong time.
Even Leeroy combo Renolocks are in big trouble versus Mage, they can't deliver the massive killer blow that easily.
BTG is the god of bad aggro players scapegoating Reno for their failure. Yes, because I defeated many pirate warriors because they went full face with weapons, leaving a minion alive on board that secured two turns of vital trading, or, at least, something to make a Defender of Argus or a Sunfury Protector valid plays.
A few days I played an Aggro Shaman vs Aggro Warrior, got full 9 damage from Spirit Claws 3 turns in a row, not because I was lucky with hero power, but because Bloodmage Thalnos lived 4 turns... And if you ask him what went wrong, probably was because of Reno+Kazakus too.
Well, sure.
But the point is, either Reno is a serious threat for Miracle - in which case no card has more overall value than Beneath the Grounds - or it is not, in which case I wonder why the whole thread was opened.