Is someone getting the best, the best, the best, the best-of-one? That simple question has plagued me and many other folk for the last few weeks. Decklists were due Wednesday night for the 64-player Mythic Invitational at Pax East next weekend, completing a stretch of me testing nothing but best-of-one Magic on MTG Arena for about three weeks straight. It's over. It's done. I can sleep again.

For those unfamiliar, best-of-one (Bo1) Magic refers to a game type played on MTG Arena comprising of only a single game. You either win or you lose (or draw, in rare Spear Spewer scenarios) and then move on to a new game against a new opponent. There is no sideboarding...well...I guess that's not entirely true. There is no sideboarding for games two and three, because there are no games two and three. However, sideboards are still relevant thanks to the existence of Mastermind's Acquisition allowing players to still access cards there.

This is a departure from traditional best-of-three (Bo3) Magic, which is the way Magic has been played for as long as I've been playing the game. best-of-three is Magic's classic gameplay. You play a game one with your maindeck, and then you get to sideboard for the remaining games, playing until one player wins two games. best-of-three Magic still exists in paper tournaments everywhere and on MTG Arena. best-of-one is just an alternate format for MTG Arena, it's not something intended to take over or replace best-of-three play.

One thing that I find important to note is that best-of-one and best-of-three are completely different formats. Yes, both involve 60-card decks built from the same card pool, but the truth of the matter is that they simply do not play out at all the same way, and just because a deck is good in one of these formats does not imply that it will be good in the other. For example, midrange decks like Sultai or Temur Reclamation are basically nonexistent in best-of-one, whereas they remain a popular choice in best-of-three play. Likewise, Mono-Red Aggro is one of the top decks in Bo1 play, but isn't a dominant force in Bo3.

One major difference between Bo1 and Bo3 play is that on MTG Arena, there exists a hand selection algorithm that looks at multiple opening hands and most of the time selects the one that has the closest to average mix of lands and spells. This hand selection algorithm is only for Bo1 play and not Bo3 play, which means that people playing Bo1 will mulligan significantly less and have nut draws significantly more often than normal Magic.

Another major difference is that decks that tend to win game one but might struggle after sideboard are significantly better than normal. Those decks might have trouble beating various sideboard hate, but since sideboarding does not exist, they are pretty difficult to combat unless you are specifically gunning for them. Nexus of Fate strategies were a prime example of this, since people can't sideboard into Negate, Duress, and Unmoored Ego. "Were" being the operative word there, as Nexus of Fate was eventually banned in best-of-one play.

Esper Control is the prime example of a deck that benefits from this dynamic. Esper Control plays zero creatures in the maindeck, which makes removal spells like Lava Coil, Cast Down, and so forth dead cards against Esper. Decks that play those cards get to swap them out for things like Negate or Duress after sideboard and improve tremendously against Esper Control, perhaps enough to win a three-game match, but that isn't the case in best-of-one play. This makes Esper Control way more powerful in best-of-one than normal.

Due to the massive differences in opening hands with the hand selection algorithm, and how that affects deckbuilding, as well as the nature of the kinds of decks that benefit from no sideboarding, best-of-one and best-of-three truly are two entirely different formats. They share mostly the same card pool, with the exception of Nexus of Fate, but that's basically it. Past that point, they are different beasts entirely. Different decks are good, and games play out differently.

I've lived and breathed this format almost nonstop for weeks straight, and even before that, I played a lot of Bo1 Magic, even when I could have just played Bo3 instead. I genuinely enjoy this format and I've designed multiple decks that have ended up being tier 1 strategies at various points over the past few months. This is a format I know intimately well, and this article is my attempt to break down that knowledge.

While this won't be relevant to people looking exclusively to play Bo3 gameplay, now that ranked ladder gameplay on MTG Arena qualifies players for major tournaments, I believe learning Bo1 gameplay is going to become more and more relevant as time goes on for many players. You can rank up with Bo3 as well; however, sometimes the best route to the top might be through exploiting the Bo1 metagame.

Lands Ahoy

The best-of-one hand selection algorithm leans toward choosing hands that most closely approximate the average mix of lands and spells in one's deck, and that has a major effect on deckbuilding, deck selection, and which decks perform best.

Low-to-the-ground decks like Mono-Red Aggro, Mono-White Aggro, Mono-Blue Tempo, or Mono-Green Aggro can get away with lower land counts than normal because of this dynamic. A Mono-Red Aggro deck in Bo3 play would generally play something around 21 lands to be able to effectively curve out and eventually be able to cast cards like Experimental Frenzy in a reasonable timeframe. In Bo1 play, this deck can play anywhere from 17-19 lands. Some especially low-to-the-ground builds of Mono-Red actually play as low as 13 lands. Although these versions aren't very good, it is impressive how much they push the constraints of deckbuilding while remaining a functional deck.

The reason this is possible is the hand selection algorithm. The hand selection algorithm is going to, most of the time, select a hand that contains the average number of lands for that deck. For a Mono-Red deck with 19 lands, that number is two. The reason a deck like Mono-Red in traditional Bo3 play will have 21 lands is because you don't get to draw multiple opening hands and then pick the best one, and thus you need 21 lands to reduce the number of opening hands with one or zero lands that will generally be mulligans. That isn't a (Risk) factor in Bo1 play. Those hands don't get selected very often.

In Bo1 play, a Mono-Red deck with 19 lands will start most games with a fairly optimal two lands, enough to function quite well. Since the deck also plays two fewer lands than Mono-Red traditionally would require, it is far less likely to flood out over the course of a game. In other words, the nature of the opening hand selector prevents the deck from having to mulligan or get significantly mana screwed in the vast majority of games, and then it also doesn't flood out very often.

It's no surprise that Mono-Red is one of the defining decks in Bo1 despite being just another deck in Bo3.

You may have noticed that all four of the decks that I mentioned as able to get away with significantly reduced land counts are all mono-color strategies. That is no coincidence. In fact, single-color strategies benefit massively in Bo1 play, and three-color decks suffer significantly. While the hand selection algorithm typically chooses hands closest to the average amounts of lands and spells for the deck, it does not look at what color of mana those lands produce or the color of spells in the hand.

For a deck like Mono-Red, this doesn't matter, all the lands are Mountains and all the spells are red. For Esper Control, this absolutely matters. The hand selector might choose a hand of three Isolated Chapels and four blue cards because it most closely approximates the average land/spell ratio of 3 lands and 4 spells. It might pick that hand over a hand of four perfect lands, Thought Erasure, Mortify, and Chemister's Insight, which is a way better hand.

When it comes to three-color decks, while their opening hands are also typically better than average, sometimes the hand selection algorithm will choose a worse hand, which is almost never going to be the case for mono-color strategies. Decks like Esper Control simply have to mulligan way more in Bo1 than other decks do, and mulligans are way more punishing, since most opponents will be keeping powerful, balanced hands with nut draw potential.

Three-color decks also need higher land counts, not just to hit their land drops on time, but also to guarantee that they draw the right colors of mana. Sometimes three-color decks play more lands than they normally would, not because it provides the right ratio of lands that they need to curve out properly, but because their fourth land might not always be able to cast their four-drop if it doesn't produce the right colors of mana, so they want extra lands to ensure they can produce the right colors to cast their cards on time.

As a result, three-color decks don't get to abuse the hand selection algorithm nearly as much as mono-colored decks do, as they still have to play higher land counts to hit their colors. They also still have to deal with games where they don't function or are clunky due to having the wrong colors of mana, having lands enter the battlefield tapped or having to excessively deal self-inflicted damage with shock lands.

Mono-Color decks do not suffer this in any way. Mono-Color decks don't have to deal with those clunky hands, and since they get their nut draw hands quite often, they also punish clunky hands from other decks with a level of prejudice not normally seen. If you have a clunker with Esper Control and you see your opponent lead on Mountain, you can probably pack it in, since there's a good chance they just one-two-three you out of the game.

No Dead Cards, No Hedging

Despite this, Esper Control is one of the best decks in Bo1 play. Esper Control, as I mentioned earlier, plays zero creatures and thus gets to abuse the lack of sideboards by punishing decks that do play removal spells that exclusively target creatures. Those decks having to draw dead cards is part of what makes Esper so powerful, and in fact, Esper's best matchups are against decks designed to prey on creature decks. It helps that nearly every other good deck in the format plays a very heavy number of creatures, which forces other decks to play removal spells or get absolutely steamrolled by the insanely fast and powerful Mono-Red and Mono-White decks.

As Esper is one of the best decks, potentially even The Best Deck, it is important to be able to beat Esper, or at least give yourself a chance to beat Esper. Decks that have the luxury of doing this, which is not every deck, should build their list to contain zero dead cards against Esper Control.

An example of this principle is the W/G Angels deck. This is a deck that I designed last format to beat the metagame, and it was successful at doing so, but the deck has remained good through this format as well. This is an updated version to adjust for the current format.

The main thing to note is that this deck plays zero removal spells, except for two copies of Ixalan's Binding. It relies on superior creatures in the Angel package to provide the right angle of attack to beat the other creature decks. While cards like Ixalan's Binding and Knight of Autumn are not particularly powerful against Esper Control, they are still, at the very least, a 4/3 for three that can attack, or a removal spell for Teferi, Hero of Dominaria or Search for Azcanta.

I've seen a number of lists that play cards like Baffling End, and I believe that to be a mistake. Decks like Mono-Red and Mono-White are already good matchups for this deck and there is no reason to play two pieces of dead cardboard to further weaken the Esper Control matchup. While that matchup is not good, it isn't so bad that it's worth just throwing away and ignoring.

Other successful decks in the format do this. Mono-Red's removal all goes to the face. Zero dead cards against Esper. Mono-White's only removal is Conclave Tribunal, which can take out Teferi or Search for Azcanta. Zero dead cards. Mono-Blue decks are cutting Essence Capture and Entrancing Melody. Zero dead cards. Golgari decks are playing Assassin's Trophy over Cast Down. Zero dead cards.

The exception to the zero dead cards plan, of course, are decks that rely on removal spells to beat the creature decks. Other Esper decks are the prime example of this. It's not possible for those decks to have no dead cards against Esper, because having plentiful removal is how they beat all the other decks in the first place. If they cut those cards, they would just lose to everything else.

In fact, there is certainly a bit of an arms race when it comes to building Esper Control. A number of Esper Control players on MTG Arena have been getting rid of more and more removal spells in favor of cards that increase their odds in the mirror, including clunky options like Devious Cover-Up or Nezahal, Primal Tide. The danger is that if you take this too far, then you begin to lose what made Esper appealing in the first place: beating the creature decks with excessive removal and sweepers.

There is a delicate balance to be had, and you have to pick and choose your battles. You have to pick which decks you want your deck to be good against, build it to beat those decks, and then let the chips fall where they may against the other decks. You can't beat everything, and by trying to beat everything, you'll just beat nothing.

The principle of trying to beat everything by adding cards to improve matchups here and there is called hedging. Don't do this. This just dilutes your strategy and makes it unfocused. The harsh truth of best-of-one is that no deck beats every deck. Accept your bad matchups and lose to them, but make sure that you don't lose to the decks you're supposed to beat by trying to beat the decks you're supposed to lose to.

The perfect example of this is the Dovin's Acuity Esper deck that I've spent countless hours working on and hundreds and hundreds of games playing over the course of 50+ different iterations of the deck. The deck is called either "I hate myself for crafting four copies of Ethereal Absolution when I didn't need to, wasting all my rare wildcards, thus destroying my legacy forevermore version 37 of 51" or "Heinous//Anus" and it's my pride and joy when it comes to Bo1 play. This deck has taught me so much about the fundamentals of Bo1.

This deck is awesome, and thoroughly destroys aggro decks. There is but one problem. It doesn't beat control decks or decks that play cards like Expansion // Explosion. It also loses to a single copy of Unmoored Ego. It's actually horrible...nay...heinous against Esper Control to the point where the matchup is very nearly unwinnable.

I spent so much time and frustration trying to tune this deck to be able to beat Esper Control. The problem is that once I would finally get a list that was able to get even close to 50/50 against Esper Control (I could never even get to even vs. Esper, only close), I would lose all my other matchups because I had to cut too many anti-aggro cards, the cards that made the deck good in the first place, along the way.

Eventually I realized what I knew all along. Hedging is bad. Just beat the matchups you're supposed to beat and take your losses. I stopped trying to build this deck to beat Esper Control, or even have game against it, and just focused on making sure I was beating the decks I was supposed to beat. My win rate was much better that way.

Metagaming

Metagaming is very alive and well in Bo1 play. In fact, metagaming is way more prevalent in Bo1 than Bo3, because there often exist decks in Bo3 that can basically beat anything once you tune the maindeck and sideboard for the format. That never really exists in Bo1 play, so you have to figure out what the format is looking like and pick decks that face up well against it.

The general principle is that aggro decks are so powerful that they can basically beat everything any given game, but they generally lose to midrange decks like Golgari or W/G Angels, and they also lose to control decks skewed to beat aggro, like Dovin's Acuity or Anti-Aggro Esper. Midrange decks tend to lose to control decks. Control decks tend to lose to anti-control skewed control decks or decks built to beat control, like Temur Reclamation. They lose to aggro if they skew too hard to beat control. Temur Reclamation and other anti-control decks beat control and midrange but get smashed by aggro.

Picking a deck based on what you're playing against the most or what the format is shifting toward is a large part of being successful in Bo1 play. If I'm playing against a ton of aggro, I'll probably start playing W/G Angels or Esper Acuity. If I'm playing against more stuff like Temur Reclamation, or Gates decks with anti-control packages, then I'd probably switch to playing something like Mono-Red or Mono-White to just smash them.

The Value of Versatility

While hedging is bad in Bo1 play, versatility is great. The key example of this is the card Chemister's Insight. Chemister's Insight is one of the best cards in the format, and I wouldn't play less than four copies of this card in any deck that wants it. The beauty of Chemister's Insight is that decks that play the card, like Esper and Jeskai Control or Temur Reclamation, are decks that rely on removal spells to beat creature decks and countermagic to beat other decks. Chemister's Insight is a rare card that lets you turn one resource into another. Azor's Gateway and Radical Idea are also cards that do this.

Playing cards that are versatile in multiple matchups, or even all matchups, is one of the biggest keys to finding success in Bo1 play. A good example of this are decks like Sultai cutting Cast Down entirely from their deck, because it's a dead card vs. Temur Reclamation decks and Esper Control decks, and instead playing Assassin's Trophy. While giving your opponent a land sounds bad, it's far less of a drawback in Bo1 play where games are much faster and more powerful, and the versatility is a massive benefit. A lot of decks, like Esper Control, only play one–two basic lands anyway. They don't always get to search one up.

Versatility also applies to ways to win the game. Decks that aren't just piles of 20+ creatures are heavily incentivized to play a versatile repertoire of win conditions. If your Esper deck only plays four Teferi, Hero of Dominaria as a win condition, what happens when your opponent decides it's time for suns out, guns out, and slams The Immortal Sun against you? It's always Sunny in Scoopadelphia.

What if your Jeskai Control deck only wins with Expansion // Explosion or Teferi, Hero of Dominaria and your opponent casts Unmoored Ego on Expansion//Explosion and then Sorcerous Spyglass on Teferi? While that sounds like an extreme case, the Dovin's Acuity deck is literally designed to do exactly that.

Playing a variety of ways to win the game becomes important to beating all the random ways that games can go or the powerful hate cards your opponent's might be maindecking. Nothing is better at this than Mastermind's Acquisition.

Mastermind's Acquisition

I'm dedicating an entire section to just this card alone. I believe that every deck, or nearly every deck, that can reasonably slot this card should do so. Mastermind's Acquisition offers the kind of versatility that can help get a deck out of any sticky situation or help beat any strategy. This card is easily one of the best cards in the format and it's a mistake to play a strategy that can utilize this card and choose not to do so.

In Bo3 play, Mastermind's Acquisition isn't that good, because you have to dedicate precious sideboard slots to silver bullets to tutor for, which means you have a diminished sideboard for games two and three when you don't get as many tools to side in and out of your deck and have to make weird decisions on what to leave in your deck vs. your sideboard.

That isn't the case in Bo1 play. Mastermind's Acquisition gives you access to 15 extra cards that aren't in your deck and you can tailor those 15 cards to precisely the exact 15 cards you think you would most use without any regard to having a real sideboard since you won't ever play sideboarded games. That is a massively powerful effect.

If you're playing a deck with Mastermind's Acquisition, you should design your 15-card sideboard to provide you with effects that can get you out of tricky situations or cards that are powerful enough to win games or pull you ahead in games.

The presence of Mastermind's Acquisition, paired with its raw power in the format means that it's not only decks that play Mastermind's Acquisition that should have a sideboard. You should have a sideboard if you have any way to possibly ever interact with your opponent's Mastermind's Acquisition as well.

If you're playing Expansion // Explosion or Dire Fleet Daredevil, build a 15-card sideboard. If you're playing Hostage Taker, In Bolas's Clutches, Thief of Sanity, Entrancing Melody, or Mass Manipulation, build a 15-card sideboard, because you could steal your opponent's Thief of Sanity, hit them with it, and hit Mastermind's Acquisition. The most extreme example is that you should build a sideboard with every deck in case your opponent casts Switcheroo on their own Thief of Sanity and your creature, and then you connect with their Thief the next turn and hit their Mastermind's Acquisition. Ok, that one's a bit far-fetched, but you get the gist.

The sideboard you should build with decks that don't play Mastermind's Acquisition but might interact with their opponent's copies should be heavily skewed sideboards. Keep in mind that you don't need to cover every situation with your sideboard, you only need to cover cards that you would actually use against decks that play Mastermind's Acquisition. You probably don't need that Shivan Fire in your sideboard, since people playing Mastermind's Acquisition are usually control decks. You'd be better served with 15 anti-midrange or anti-control options instead.

Sideboards in this format aren't real sideboards. They are just silver bullet extensions of decks.

Win the Die Roll

The hand selection algorithm creates a format that rewards mono-color aggressive strategies, since they consistently get powerful, balanced hands, and don't flood out as much, as I mentioned above. The fact that these decks so often have nut draws further exacerbates the advantage of being on the play in constructed Magic. This is a play/draw dependant format, more than any other format I can ever remember playing.

Sometimes, even with a great hand, being on the draw simply means you will lose because you cannot ever catch up to the just-as-great hand your opponent had on the play.

I'm going to post some numbers here. For all the decks that my testing teammates and I played at least 100 or more games with while preparing for the Mythic Invitational, these are the play/draw win rate deltas. In other words, these are the differences in win rates between being on the play versus being on the draw for the decks we played the most with. I'm not matching them up with the decks themselves so as to avoid giving away what decks we tested most with. While I'd love to talk about the decks I registered, and posts stats and lists for the top decks, it wouldn't be fair to myself or my teammates to do so.

12.05%
21.95%
11.3%
21.06%
22.18%
12.79%
10.98%
24.54%
15.79%
27.98%
16.05%

This is a relatively small sample size in some regards. This only represents about 2000 games of Magic, which is a lot for a few individuals, but not in the grand scheme of Magic as a whole. Still, if these numbers are to be trusted, it seems as though there is somewhere between a 15-20% difference in likelihood to win a game based on whether you won the die roll or not. That's pretty extreme. Please, Wizards of the Coast, do something to balance the die roll better so this is closer to 50/50.

Can't Win Them All...Or Any of Them Really

One of the biggest keys to being able to play Bo1 with any level of longevity is to accept that you will simply lose a lot of games you play and there is nothing that can be done about it. Brad Nelson was getting really frustrated testing best-of-one at first and eventually I told him something along the lines of "Brad, you're used to playing Bo3 where you win every single match. That's simply not the reality of this format, you're going to get smashed a lot no matter what you do." Thankfully, I'm used to losing early and often so I finally found a format that suited my style. It was an easy fit for me.

It's totally possible to have a great win percentage in Bo1 play. Mine was around 70% last I checked, which is pretty good for Bo1 or Bo3 play. But a lot of games are fast and brutal, and you will lose those games. The key is to just brush it off and join another game and not let it eat at you. If you're someone who can't stand occasionally being helpless while you lose, then I would strongly suggest either learning to get past that mentality or not get too invested into this format.

The format can be very streaky too, because a lot of it depends on what decks people are joining up with and how the metagame is shifting. For example, I had a deck where I won ten consecutive games all the way to #9 ranked Mythic player and I was extremely excited about it. Then I went 6-9 in my next 15 games, playing often against people metagamed against it, and suddenly hated the deck again. A little while later I went on another hot streak with the deck and liked it again.

Playing the Games Themselves

Due to the powerful nature of the games played in Bo1, as both players tend to keep seven cards and have good hands, it's important to know how to play out the games themselves. My general rule of thumb is that they always have it and I tend to play as though they do. What I mean by that is that they probably aren't going to miss their third land drop, and they probably are going to have relevant interaction early in the game. More often than not, your opponent has a good hand and is going to be able to make a reasonable to strong play that their deck could offer up for each turn, especially early in the game.

With that being said, because of how powerful the decks and hands are, I think it's generally a mistake to play conservatively and defensively and play around too much. You don't have the luxury of taking turns off doing nothing. If it's a decision between jamming or holding back, I tend to err on the side of playing my cards out and hoping it works. If you're playing an all-in deck, go all-in. You have to get your cards out there early and often and try to keep pace with your opponent.

I also think that hands that don't do anything until turn three on the draw should be mulligans most of the time, unless they have good catch-up mechanisms, like Kaya's Wrath or Lyra Dawnbringer, etc. You just don't have time to do nothing on the draw against the fast decks, and even the control decks have time to set up if you don't interact early. I also mulligan any hands that are really clunky, like too many three- or four-drops in my aggro decks or too many taplands or four-plus mana cards in my control decks. Hands have to be mulliganed more aggressively in this format because games are faster and more brutal, but at the same time, mulligans do happen less often.

And that was the best-of-one million words. I didn't even have an opportunity to cover specific decks, lists of those decks, and how they match up against other decks, something I hope to cover in the future once I no longer have to shield that information due to the Mythic Invitational. I'd love to share that information and help people master this format that I love...and also loath. It's truly is a love/hate relationship. I love it on the play and when I'm winning, and hate it on the draw and when I'm losing. So, like any true Magic player, I hate it all the time, because I never win my die rolls!

I think there is a surprising amount of depth to this format, and at the same time, most of the best decks are extremely generic strategies. It's really an enigma, and I can't explain why I love it so much and why it frustrates me still. It's a beautiful thing, and I can't wait till War of the Spark comes out and I get to try to figure out how to beat the best-of-one metagame once more. That's truly the best of fun.