While most monks might hone their strength through isolation and careful introspection, monks of the Way of the Brawler train through street fighting and underground brawls. A loose collection of pugilists and bruisers, they develop their techniques through sheer muscle and moxie. Though their methods may be unorthodox, any who might question their capability will soon learn of their indomitable prowess in hand-to-hand combat. 

Often brash and bullheaded, monks of this nature are unlikely to hold much respect for more austere tradition. They may otherwise be indistinguishable from the average townsfolk outside of a fight. To these monk, lessons learned in a bar fight or fighting ring are far more valuable than tutelage in some dusty old temple

Gumption

When you choose this tradition at 3rd level, your fighting experience allows you to push your body to incredible feats. You can use your strength or Wisdom modifier whenever you make any Strength (Athletics) Check. 

The Ol' One-Two

Starting at 3rd level, your confidence swells alongside your successive blows. Whenever you damage an unmarked creature with an unarmed strike, you can mark that creature until the start of your next turn, or until you deal damage to that creature with another unarmed strike. You have advantage on any attack rolls of unarmed strikes that you make against creatures marked by you. 

Cross-Counter

At 6th level, you can react to enemy attacks with stunning agility. When a creature within your reach attacks you, you can use your reaction to impose a disadvantage on that attack. Immediately after that attack, you can spend 1 ki point to make an unarmed strake against that creature, as part of the same reaction. 

Haymaker

By 11th level, you learn to seize opportunities in your foe's defense to throw especially destructive punches. When you use your Stunning Strike feature against a marked creature, you deal an extra 2d6 force damage.

Thunderous Fists

At 17th level, you can imbue your fists with supersonic power. You can cast the knock spell at will with a range of 5 feet. Additionally, immediately after you take the Attack action on your turn, you can spend 2 ki points to cast Thunderwave spell as a bonus action. 

You can spend additional ki points to cast Thunderwave as a higher level spell. Each ki point you spend increases the spell's level by 1. The maximum number of ki points (2 plus any additional points) that you can spend on the spell is equal to half of your monk level.