I’m a little bit late to the party, but it seems that the Magic community has been discussing the looter problem quite extensively lately. So here is my take on the question.
To recap, the question can be stated as, if you had the second best card of your deck in your hand, should you loot or not? The downside of looting here being that you might draw the actual best card in your deck and would have to discard the second best — bummer!
Assuming about 25 cards left in your deck, this is a 4% chance of drawing your best card and having to discard your second best. But if that were to happen, would that really be that bad? After all, you are still improving your hand. This is the thing with looting, it always improves your hand, no matter what.
These are pretty much the arguments in favor of looting, you always improve your hand, it’s very unlikely to draw your best card, and you are getting 1 card closer to the best card in your deck.
However, I think this is an over-simplification of the problem, and I don’t buy it. The issue with this reasoning is that it only takes into account the immediate impact of looting. In the span of that one turn, yes, looting is the better play. But, if the game actually goes longer and you need to grind your opponent out, then you might wish you didn’t thin out good cards from your deck.
First, we need to realize that looting might actually make your hand weaker in some situations. Imagine the next cards in your library are a card of the same power level as the card you currently hold and then two lands. If you blindly loot, you will draw the other good card and you have to discard one of them. Next turn you draw the land, try to loot it away, and replace it with another land. You end the turn with one good card and one land. Alternatively, if you skip looting this turn, then next turn you draw your good card, skip looting again, and end the turn with the two strong cards in your hand. You are clearly better off by declining to use your looting ability.
The above is obviously a very specific scenario, but it serves to demonstrate that looting might not always improve your hand, if you take into account future turns. And in the end, this is not so uncommon. Does the situation fundamentally change if you replace the strong card by any spell in your deck? Not really, if you loot, you end up with one spell and one land, if you don’t, you have two spells. All it takes is for the following three cards in your library to be one spell and then two lands.
And there lies the main problem with the justification of looting in that situation, it does not take into account deck thinning. I know that deck thinning is often overrated, but it becomes a real thing over a long game with repetitive looting effects.
Again, we can take it to the extreme to see what would happen. Suppose we play such a long game that we get to draw all of our spells. If you were to loot every turn you have nothing to discard and already have one of your stronger spell in hand, then you would be milling some of your spells every now and then. When you get to the end of the game, you might have lost 5 to 10 spells, and would have had to fight with a smaller number of spells. On the other hand, if you wait to loot when you have something that is really dead, like an extra land, then you will be able to play the game with the totality of your spells, which will eventually turns into significant card advantage.
As a small aside, this kind of looting is very different from a self milling effect, and I am not stating that self milling is a negative effect. In most cases, self milling has no impact as the order of your library is truly random and you rarely end up milling yourself. The key difference with looting here, is that by looting over the course of several turns, you manage to turn all your dead cards into actual impactful cards, which gives you card advantage. Essentially, it is not a random milling effect, you choose which card goes to the graveyard. But you can waste part of that card advantage if you loot away actual impactful spells. If you don’t have access to that kind of card selection, a few self milling effect will not impact you, and if you have graveyard synergies they actually become a bonus.
I hope it is by now clear that if the game lasts long enough, you are not optimizing your win percentage by choosing to loot. I think the choice whether or not to loot is extremely complicated, and I would certainly not advise you to follow the heuristic “if you don’t have the best card of your deck in your hand, just loot”. The decision is dependent on the board, how good your deck will match the opposing deck in a long game, the density of spells left, the amount of time you have, and many more factors. The key to become a truly good Magic player is to be able to recognize all the subtilities involved in a decision, and to think beyond the short-term implications of a play.
To answer the original question, if I had the second best card of my deck in my hand, without extra information I would advise not to loot. I don’t think you accomplish much by looting, as it is very likely that you will be just milling the top card of your deck, and in the rare case you actually draw the best card in your deck, it is not at all clear that you end up in a better shape by having to discard a strong card. Waiting one turn and making sure you can start filtering out dead draws seems like a better plan to me.
That said, there are situations where I would decide to loot. If I absolutely need to get to a better card than what I have in hand, or if it is clear that the game is gonna end in 1 or 2 turns, I think you are giving yourself better chances of winning by just seeing more cards.
It also depends on the quality of the cards in your hand and deck. If you hold an average spell, and there is a card in your deck that is so much better than the rest, then you probably want to loot, even if that means you will have to discard actual spells. If, on the other hand, your deck is full of average spells, then you may want to not loot and just go for raw long term card advantage by preserving every single spell in your deck.
I hope I manage to convince you that the looter problem is not straightforward and has many intricacies. My answer to the problem as discussed in the community would be “do not loot!”, but I can certainly understand people that choose to loot. But please, don’t just loot because “it always improves your hand”, there is so much more involved.