Granted this is all personal experience with no testing or medical backing, I'll share what I've noticed myself.
Greatest contributers:
Denial- If I get close several times and either stop and go back to more foreplay to settle down and let it all build up, it's normally more a spray.
Duration- If I go for longer, I get more bang for my buck. More built up tension, and more range/content.
Pushing- This is harder to explain but I noticed it when masturbating a while back, it seems if I contract the muscles of my stomach down as if trying to force urination, it increases the power behind my orgasm (and actually feels even better)
I don't know if any or all of this is true for other men, or if it's unique for each guy. Some may just be destined to spray, ooze, or vary, but hopefully my post assists someone out there somehow.
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