Momentum Canceling is a very important element of Super Smash Bros. Brawl's competitive play. The concept is that certain attacks will halt or reduce a character's aerial momentum and allow them to survive at higher percents. Combined with the ability to attack and air dodge while tumbling or reeling in Brawl, this makes it possible to use these moves to avoid being KO'd. Momentum Canceling allows for survival around 10-15% longer than you normally would be able to, although it is very character dependent.
There are two different types of momentum canceling: vertical and horizontal.
Vertical Momentum Canceling
Vertical Momentum Canceling is useful for preventing a character from getting Star KO'd. To do this, simply do any aerial attack as soon as possible after being hit and fast fall as soon as the aerial starts. This can be done slightly faster than normal by pressing down on the C-stick (because the C-stick fast falls the Down Aerial automatically). The effectiveness of this technique depends on the difference between the character's normal fall speed and their fast fall speed.
Horizontal Momentum Canceling
Horizontal Momentum Canceling is used in order to prevent being KO'd off the sides of the stage. This is much more character dependent than Vertical Momentum Canceling, but the basic idea is performing the character's fastest Aerial Attack (or an air dodge) and then jump toward the stage. The jump helps cancel some momentum and the aerial/airdodge allows characters to jump sooner than they would normally be able to.
The chart here shows each character's aerial or airdodge that ends the soonest (the one that is best for Horizontal Momentum Canceling). Meta Knight's Uair is the fastest, only 13 frames!
Special Moves with HMC
Many characters have Special Moves that cancel their Horizontal Momentum better than a jump. These special moves can be found below.
- Luigi - Green Missile (uncharged)
- Peach - Peach Bomber
- Donkey Kong - Spinning Kong*
- Diddy Kong - Monkey Flip
- Yoshi - Egg Roll*
- Meta Knight - Glide
- Pikachu - Skull Bash (uncharged)
- Jigglypuff - Pound or Rollout (lightly charged)
- Mr. Game and Watch - Oil Panic*
- Ness and Lucas - PSI Magnet (after aerial)
The moves with a * indicate that they stop momentum completely