This is a little ironic coming from you, Z. I've engaged you over random topics in the past, and more than once if I've referenced specific studies, facts, wording, etc. you've come across as annoyed and have said that you view things here as friends talking in a bar, not a debate team. I was a little put off by that, but fine.
Yet here you are doing... what, exactly, with this opening blurb? Do you want me to dig up some studies on the variance in athletic performance with subjects under different reported states of mind? Because, since we're talking about something that we both know can't be seen with the naked eye or measured with a specific tool, we're going to be talking about a lot of correlative data that may suggest an occurrence or phenomenon, but won't conclusively prove it. But such is the scientific method, and while I'm fine discussing it and it's merits with you on this, it's not the type of banter you're likely to encounter at the local pub.
My comments above were presented in a more casual fashion. I do think momentum can have an effect in there somewhere, but I also know there's no definitive way to prove how much and when, so I left plenty of outs. That doesn't seem good with you, either, as then you turned to citing cases and took what appeared to be a passive-aggressive jab above. There's no need for stuff like that, man.