Standard Boros Aggro Deck Guide: The Highest Win Rate Deck in Best-of-One

Hello everyone!

It has been a hot minute since I’ve had (ironically) had the time to get back into best of one, but I’m glad that I am! Bo1 is fantastic just to get on Arena, jam out a few quick games, and go on to do whatever else you have to do today. However, for some people it’s their preferred format as you just get a different metagame from Bo3 or you just like facing a new deck with each run rather than spending a bunch of time in the same matchup.

Nevertheless, rather than extolling the virtues of Best of One magic, let’s talk a bit more about the deck I’m covering today, but for that, let’s establish some context. There’s a lot of variety on Bo1 ladder, but for the vast majority of decks you can separate them into 2 categories: aggro decks or anti-aggro decks.

For aggro decks, you get an inherent advantage as you’re very fast at the expense of having good interaction or good reach. Now this isn’t to say you have none, in Mono White Aggro for example you could have Skyclave Apparition and/or Brutal Cathar for interaction or Cave of the Frost Dragon for reach, that’s pretty much the extent of it.

I digress, if you’re playing an anti-aggro deck, you give up speed to have interaction and “reach” in the form of inevitability. This is more or less the dynamic that every deck follows and the metagame has yet to see a deck that realistically had it all and was still a good deck. That is, until recently anyway!

No aggro deck before Boros was able to be a strong deck, have interaction, and reach which is obviously a huge deal in a format that only lets you play one game! Mono Red Aggro was the closest, but the card quality just wasn’t there, but for Boros, that’s no longer an issue.

Like any good aggressive deck, you always have to start at 1 mana to achieve a strategies maximum speed. Here we have two one drops between Hopeful Initiate and Kumano Faces Kakkazan.

Hopeful Initiate is the new one drop of choice for White decks as, in exchange for immediate power, you have a threat that can continue growing as long as you have larger creatures to attack with. Furthermore, you get a bit of additional value with Initiate’s activated ability to Naturalize something if you have errant mana and +1/+1 counters.

Kumano Faces Kakkazan on the other hand is just one of the best 1 drops Standard has seen in a long time. Similar to Hopeful Initiate, you give up some initial speed with Kumano, but you get a pretty substantial payoff for your patience. A card that will always deal 1 damage then provide 3/3 in total stats is pretty absurd for one mana!

Moving up the curve, we have our very powerful 2 drops! Likely the best 2 drop in Standard, Luminarch Aspirant has been a staple in White decks since it’s printing and is still going strong by the virtue of it’s strength. It seems that growing any creature every turn is a pretty strong ability!

The second 2 drop hasn’t been as popular, but is still quite powerful in Bloodthirsty Adversary. A 2 mana 2/2 with Haste isn’t a super exciting stat line, but definitely reasonable. However, you also get a nice pseudo-kicker ability that, in the late game, grows Adversary and lets you flash back an instant or sorcery for free! With that level of versatility, it’s definitely a worthy inclusion in the deck.

Moving up yet again on the curve, we have our 3 drops. For starters, we’re playing Brutal Cathar as an additional piece of interaction in a metagame that definitely warrants it. There are so many creature decks that any piece of removal you can get your hands on you want to play.

However, it also has some neat synergy with the spiciest card in the deck: Sunrise Cavalier. I’ll admit, prior to seeing this deck, I didn’t know this card existed. This may seem weak on the surface, but it plays out much stronger than it looks. Back when I played Mono Red Goblins in Bo1, I was always surprised how good Hulking Bugbear felt just as a 3 mana 3/3 Haste, and this is strictly better with Trample! Not only that, but with each Day/Night switch, Cavalier will give you a +1/+1 counter on any creature you want for your trouble! This won’t happen terribly often, but definitely often enough to be relevant.

Lastly, it synergizes extremely well with the final threat of the list, Thundering Raiju. Raiju is an absolute monster as it comes in and immediately starts hitting hard as it can grow your other threats on top of dealing damage to the opponent on attacks. It’s most reminiscent of Hellrider, and while obviously not as good, it being relatively close definitely speaks to the power of Raiju.

Now let’s be honest, having good threats in an aggro deck isn’t the hardest bar to cross. However, as I said before, what sets this deck apart isn’t the threat quality (although it is definitely very high), it’s the removal.

Getting access to both Play with Fire and Roil Eruption is so good for an aggro deck and what they were sorely missing for a long time. The fact that they can be cheap removal that can get you a huge tempo lead in aggro mirrors or reach when you need a few more points of damage to close out the game should not be underestimated. With a deck that is as aggressive and punishing as this one, having these removal spells in concert with the haste threats can make traditionally bad matchups very winnable as you can kill the opponent out of nowhere.

Finally not to leave it out, Valorous Stance is the lone 1 of in the list as a versatile removal and protection spell that’s hardly amazing, but always solid.

Overall, this deck has every tool that an aggro deck would want and a high quality of threats so it definitely makes sense that this is the highest win rate deck in Bo1 right now.

Notable Exclusions / Potential Inclusions

Intrepid Adversary

I believe that this is a bit weaker than the Bloodthirsty Adversary as we don’t necessarily go wide, but it’s definite not unreasonable if you’re privy to it.

Thalia, Guardian of Thraben

Despite playing a lot of cheap spells, it wouldn’t be super unreasonable to play Thalia anyway. I don’t think it’s strong enough, but it wouldn’t be a silly option either.

Adeline, Resplendent Cathar

You can probably tell that this deck is avoiding double pip cards to make everything more castable and Adeline is the perfect trap. It seems like this would be easy enough to cast, but by the math, you would want 18 sources to reliably cast a 3 drop on 3 and we only play 14 including Pathways! This would be stranded in your hand often so definitely not worth your while.

Elite Spellbinder

This card’s great! If you’re not convinced by Sunrise Cavalier, then Spellbinder is probably your next best option.

Legion Angel

This is similar to Adeline, but has two distinct advantages. One, it’s a mana more expensive which gives you more time to get your double white. Second, just playing one Legion Angel and 3 in the board is both extremely powerful and it’s not the end of the world if this is a bit harder to cast as the odds of you drawing it most games is rather low so you’ll see a higher density of cards before finding it.

Rabbit Battery

This used to be a play set in older Boros Aggro lists, but I think the card was a bit overhyped. It is solid, but it’s less impactful than the other 1 drops and the upside is mitigated by having a higer density of haste threats.

Kami's Flare

This deck isn’t a dedicated modified deck, but has enough +1/+1 counter synergies to justify including this. It would likely be too many spells, but swapping out the Valorous Stance for this at a minimum would definitely be reasonable.

Fable of the Mirror-Breaker

This doesn’t necessarily synergize with the deck, but it’s so good it’s always worth considering. I’m unsure if this is better than Sunrise Calvary in this deck, but I wouldn’t be surprised if it were.

Reckless Stormseeker

This is extremely similar to Sunrise Calvary as they both attack for 3 on 3, but since we already have a lot of Haste threats, I do like Sunrise Calvary more right now.

Flame Discharge

Everything I said about Kami’s Flare applies here, but as far as 1 ofs go, this definitely makes more sense than Flare. I am a huge fan of 1 of Fireball effects in general.

Angelfire Ignition

Another excellent 1 of choice, Ignition is a great top deck at all stages of the game and drawing multiples is pretty bad.

Blade Historian

More excellent 1 ofs! This is an obscene top deck i the late game and we don’t want too many 4s, definitely a consideration.

Showdown of the Skalds

Playing Boros Aggro and not playing Showdown feels like sacrilege, but this deck is trying to kill the opponent as fast as possible. Showdown is obscene, but is by nature a bit of a slower card so not including it seems crazy, but hasn’t been terribly missed thus far.

Tips and Tricks

• Keep in mind that Hopeful Initiate can use the activated ability to remove two counters from ANY of your creatures, not just Initiate itself.
• If you have the Hopeful Initiate into Luminarch Aspirant curve, consider growing the Aspirant instead of the Initiate with the triggers as Initiate can grow from Training. This is unintuitive since you generally want to spread counters as Luminarch Aspirant is a lightning rod, but if you think the coast is clear, it’s an extremely brutal curve.
• You can use the “kicker” ability of Bloodthirsty Adversary without having a spell in the graveyard.
• It isn’t unreasonable to let Day switch to Night rather than casting a spell with Sunrise Cavalier if the counter can help you out scale a threat, removal, or you’re sandbagging threats.
• Be careful with the Day/Night cycle when casting Brutal Cathar as you’d hate to think you’re going to get an exile just to get a 3/3.
• 99% of the time you want to spread out counters with Thundering Raiju, but be cognizant of the opponent’s potential removal as it may be better to grow the Raiju initially. Would hate to get it hit with Strangle!
• This may be obvious, but don’t forget that you can put a stop on your upkeep to hit the opponent with Play with Fire to help smooth out your draws.
• Although getting the Kicker on Roil Eruption is awesome, it’s extremely unlikely it’ll happen so don’t put too much credence on trying to get it.

Competitive Boros Aggro Deck Guide

Want to go the extra mile? For more detailed matchup information and a sideboard guide for best-of-three, check out our companion competitive deck guide on Boros Aggro:

Standard Boros Aggro Competitive Deck Guide: The Potential Best Aggro Deck