The primary reason I've heard for not trying Brawl has been the pending rotation. There are a lot of Commander players who think Brawl sounds interesting, except for the rotation. Some players simply don't play very often, so updating their deck every three months with new cards means that they barely get to play with the deck at all between updates. Having a big chunk of the deck disappear when sets rotate out just doesn't make sense when you barely got to play with the deck as is! Other players just hate the idea of spending money on a deck, only to have to spend more money again with each set, then see the deck disappear, or demand a huge rehash, on rotation.
I completely understand, and relate to both of these issues. I generally only get to play Magic once a week, so I often play a deck only once a month or less. For Commander, that's not an issue, since I'll still get to play a deck several times before rebuilding. For Brawl, that means you've hardly played the deck before you have another set of cards to add, and more importantly, it means you've built a deck you only had a chance to play maybe ten times before half the cards have to be removed!
I have always been a player who preferred to wait for the cards to rotate out of Standard before buying them. Most Standard staples tend to drop significantly in price after they rotate out of Standard, since the demand for the cards drops away. This lets casual players jump in and get the cards for cheap, assuming you could wait until the rotation, and that was rarely a problem for me.
As far as the cost aspect, building Brawl decks hasn't been all that bad. The decks that I've built generally involve two or three expensive cards, and the rest are bulk rares or draft chaff. The format has been enjoyable enough to justify the costs, especially when I consider that I would have likely bought the expensive cards on rotation. If a card costs $5 now but would only cost $1 after rotation, buying it now for the Brawl deck really only cost me $4. The fun of Brawl decks is worth it for me.
Between not playing often and cost, how do we turn the Standard rotation from limitation to liberation? The obvious solution is to play the decks more! If you are playing more often with the decks, you are getting more chances to use the decks before making edits and getting more value for the dollars you are spending! So how do we get in more games with the Brawl decks we have? I've run into two variants that have very different ways to provide a solution to this problem.
Eternal Brawl is the variant you've more likely heard of, but never really considered. The basic idea is that you build your Brawl deck using the restrictions for Brawl, but when the Standard rotation hits, your deck is still legal. You can still alter your deck and upgrade it as much as you want, but you can only use the cards that were legal in the old Standard environment. In essence, you are freezing the last two years in time and using that deck. This keeps the power limitations for Brawl decks in place since you are still limited to a two-year stretch of cards! Eternal Brawl decks from different times will have different caps on power since they'll have different cards available, but most who have tried Eternal Brawl have found the variances in power level aren't much different than what you would find in regular Brawl decks.
This format gets particularly interesting when you backdate it. Why limit building to just the current Standard? Do you have a favorite card from Time Spiral block? Build a Brawl deck using a Standard format that included Time Spiral block! Perhaps Return to Ravnica holds special meaning for you. Build from that time!
My friend Brandon Isleib embraced the idea of Eternal Brawl immediately, particularly the idea of building some of the older Standard formats. He found the decks he was building tended to play fairly well against each other, so his initial concern that some Standard blocks would be broken against others tended to be unfounded. His love for the format has made him the de facto expert when it comes to this particular variant. He is close to building a deck for every Standard format that has existed, so it is safe to say that he has delved deep into the format!
Eternal Brawl really addresses the limitations of the Standard rotation and makes it into a feature. If you are someone who only gets a chance to play with their decks once a month, you now have a format that lets you keep your deck together permanently, so any changes or edits can still happen after you've had a chance to play the deck several times. Eternal Brawl also addresses the cost issue since you can use the deck for as long as you like! While you can argue that the cost for some of the older Standard formats could be higher, the same can be said for regular Commander decks, and Eternal Brawl decks are smaller and with the more limited card pool, you tend to have more cards that cost pennies than many Commander decks.
If the idea of an Eternal Brawl deck seems daunting due to the number of Standard formats to choose from, Brandon can probably help you out. Check out eternalbrawl.wordpress.com for all sorts of breakdowns of the format. Brandon has lists of the various Standard options, as well as links to Standard sets if you have a particular Commander in mind from an older time. The site is thorough and well-maintained. And if he doesn't have what you're looking for, or you want to talk about Eternal Brawl and get some interesting ideas, Brandon is usually available as @earthdyedred on Twitter to share what he knows. He has also started an Eternal Brawl article series that you can find here.
Transformer Brawl involves decks that are definitely more than meets the eye. This format involves building a Brawl deck just as you normally would. Then you build a 60-card sideboard for the deck – the sideboard is shuffled into the deck, transforming it into a Commander deck! I love this idea, since it takes your Brawl deck and allows you to play Commander with it. This gives you so much more use of the cards from Brawl, since you'll be using the deck in Brawl games and Commander games! When your Brawl deck sees a Standard rotation and many of the cards rotate from your Brawl deck, the deck can simply become a Commander deck that can be added to your repertoire!
When I first heard about this variant I loved the idea, but I was concerned about the logistics. When you shuffle the sideboard in for a game of Commander, how do you remember which cards to take out when you Brawl? Will I need to pack a list of the Brawl deck around with the deck so I can properly de-sideboard when I need to? This issue is neatly solved by a second deckbuilding limitation: the cards in your sideboard must not be Standard-legal! This makes it easy to separate the Brawl deck out, simply by sorting through the deck and removing every card with a set symbol from a set outside of Standard! I love elegant solutions and this one is perfect!
A further benefit to this variant comes when the Brawl deck rotates out of Standard. Now you are left with just a Commander deck that isn't particularly optimized for Commander. It is likely that there are several cards that you have wanted to add to the deck that you weren't able to because of the restrictions in Transformer Brawl; I've never met a Commander deck I've built that is completely finished and tinkering with them is part of the fun of Commander. Now you get to make further alterations to your Commander deck based on the games you played, since you've had several games with the deck (and versions of it) over the past two years!
Here is an example of a Transformer Brawl deck. Credit to TRK27 for this fine Teferi, Hero of Dominaria/Azor, the Lawbringer deck!
One of Mark Rosewater's most famous catchphrases is, "limitations breed creativity." These variants take a limitation to a format and found creative solutions to the issue. My thanks to Brandon Isleib for championing Eternal Brawl and to Joakim Karlsson for bringing Transformer Brawl to my attention! I hope these variants encourage those of you who haven't tried Brawl because of the rotation issue to give it a shot. It is proving to be an interesting format that everyone should try!