I would say that if heavy sideboarding can’t make you favored, it’s not worth the slots. Either refocus on shoring up your positive matchups or improving closer ones. The reality is that if those decks end up being a heavy share of the metagame and you’re barely even with them with heavy sideboarding, you’re likely better switching decks.

Thanks for the answer. This was very informative for me. I’m employing a similar philosophy against Affinity as Merfolk.

So say you are weak to an archetype. Let’s say “fair” creature combo (infect, deaths shadow, kiln etc)

Let’s say those matchups are very hard for your deck. If, post sideboard, it’s still not particularly good, do you think that it is better to simply double down on beating what you beat and accept an archetypal bad matchup?

I’ve been thinking about this lately. I haven’t won any post board games against infect (and likely the same vs shadow etc) with my favorite deck. The sideboard helps but not enough to equalize.

I’m considering to not bother with sideboarding for that whole archetype so I can almost guarantee a win vs control, aggro, spell combo, and big mana.

With a singular deck it makes sense to not bother and hope to dodge but an archetype?

Expanding understanding is a permanent improvement, and I attribute these articles to almost all of my mediocre success in modern (mediocre is better than none, which is where I would’ve been)

This is a question that depends very heavily on context, though I’ll answer it the best that I can. The goal is to maximize your odds to make the elimination rounds, and in an event like a PPTQ this means losing at most one round. As such, I want my deck to be as well-rounded as possible. The example that I’ll use here is Grixis Delver versus Dredge. I think the matchup is very bad, and feeling good about the matchup involves heavy sideboarding. Dredge isn’t popular in my area, and as such I believe I can commit to taking the loss. Let’s say that I expect a lot of Dredge though- this means that I will need to heavily bias my sideboard to beating this deck. I’m fine doing this if I see it being relevant, though at this point I would almost prefer to just switch to a different deck, unless the popularity of Dredge means I can cut something else from my sideboard. Mostly the spectrum is that if the deck is unpopular, I’ll take the L, and if it is popular I’ll try to bias heavily or will consider major changes to my deck selection.