Having a good manabase will win you games
The ban of Nadu sets a precedent for future Commander bans, raising uncertainty about whether investing in specific decks is worth the risk
Thanks to a handy spread of MTG colors and this general synergy, Admiral Beckett Brass is one of the most popular MTG Commanders for pirate decks
It easily locks opponents out of the game with cards like Knowledge Pool and provides you with endless counter protection
Being a 4/4 with vigilance and trample is also quite helpful, as it allows the possibility of threatening lethal commander damage without giving up access to its ability during games that run long
There are truly, truly unique decks like Elves, Fog, Bogles, Dredge, and many others but they tend to be tier-2 and lower