I only use Stretching if I am collecting data or balancing condition.
(If I did 'true power training' of Stretching x6, Cardio x2 and Match Practice x1 on hard, every hour, where speed is the watchword, then I'd include that...but I don't. )

Because putting the actual probability/chance aside, imo, stretching just gives the engine another opportunity to injure, for little gain.