Flexibility will help improve speed

[Scrap]

All movement is memory, your memory is in Neurons. Bad memory bad action, the Neurons get a Healthy memory by correct stretch. Go through the body completely it works all or nothing the body so stretch everything.

[Trainer Monkey]

All movement is memory, your memory is in Neurons. Bad memory bad action, the Neurons get a Healthy memory by correct stretch. Go through the body completely it works all or nothing the body so stretch everything.

To add on,your mind is conditioned to protect the body,and making a tight muscle fire,is abhorrent to your subconscious survival instinct,your mind knows the muscle might tear,leaving you unable to defend yourself. So it wont let you do it the way you want to.
I dont think there's anybody whose sparred or fought that didnt have a moment where "There it is" but they hadnt stretched and hydrated properly and had their own body and sub-conscious collude against them,and just couldnt get the shot off.
When I get a chance,Ill post up a series of stretch pics