Pivoting, or DA Dashing, is a technique in Super Smash Bros., Super Smash Bros. Melee, and Super Smash Bros. 4 that lets a character use attacks out of a dash.
In Smash 64 and Melee
In Smash 64 and Melee, the technique is the use of the time frame at which a character turns during a dash; any normal ground options are available as if the character were standing still - smashes, grabs and tilts can occur here without the lag that usually comes from using these attacks after a dash. Normal pivoting is primarily used so that a character can quickly change the direction they are facing whilst not suffering the usual turn-around lag that would occur when doing so. This can allow characters to improve the utility of various moves in certain situations.
The tactic was discovered by Philly Billy.