The Ally Combo is a combo Mario can perform in Super Smash Bros. 4 and Super Smash Bros. Ultimate. It involves Mario performing an up throw, then following it with his down aerial before finishing the combo with another aerial (commonly a forward aerial) or Super Jump Punch.
The Ally Combo is named for Canadian smasher Ally, widely considered to be the best Mario player in the world during SSB4's lifespan.
The combo is performed by doing an up throw into a full-hop down aerial. The player can then follow up with any of Mario's other aerials, typically forward aerial for optimal damage or up aerial for coverage and extended advantage situations. Up aerial is predominantly used as a finisher in most cases due to forward aerial not being true with certain DI.
In Super Smash Bros. 4, it is not a true combo. The long delay before down aerial's final hitbox allows characters with an air dodge or attack that is active before frame 4 to escape from the move, thus ending the combo. Since the combo is performed close to the ground, an opponent that air dodges will end up in landing lag by the time Mario's down aerial ends, allowing Mario to punish them. This means only characters with fast attacks can reliably escape the combo. This combo generally works from around 0-30% on middleweights, though down aerial will send too far to follow up with other aerials around 15-20%.
The combo is more effective in Super Smash Bros. Ultimate. The universal 3-frame jumpsquat change makes it easier to perform. Additionally, down aerial's final hit comes out two frames faster than in SSB4, making it a true combo. Down aerial's increased damage also makes it a stronger combo overall.