Optimal DI against Usmash is mostly out, slightly down (angle 339 specifically, pictured to the side.) This can extend how long you will survive by around 6% longer compared to no di and 7% longer compared to worst possible DI. This means that, while you will survive longer with perfect DI, the difference between just holding out and actually perfect DI is negligible. (0.5% difference)

Optimal survival DI against Dair is tricky, as positioning and percent changes what is best.

• DI straight to the left or right will help reduce your vertical launch distance, which can cause Dair > Usmash to not kill for 1-2% longer than normal, and can help cause the scoop hit of usmash to whiff, which, when hit, will kill 4% earlier than without it. However, horizontal DI can also keep you in range of other Dair confirms for longer, such as Dair > Fsmash. Generally, due to the amount of overlap between the two windows, this is often not a concern and so one should DI to the side most likely to avoid being hit by the Usmash scoop and/or Fsmash.

• When at higher percent, no DI is optimal as it will maximise vertical launch distance, which will cause Usmash to whiff sooner than horizontal DI. No DI will cause Dair > Uair to kill slightly sooner, but Uair and Usmash have a large gap in between their kill windows, making this not an issue to be concerned about.