Is My Success Simply Variance?

[Romanov]

I would like to figure out how likely my NBA record of 36-18 is simply variance. I have done this (binomial) to see the probability that if I am actually a 50% bettor, I would have a 36-18 run:

(54 choose 36)*(.5)^54 = .00538

Also, to find a run of 36 wins of 54 bets or better I normalized the binomial (I know very little about statistics so show me if I am wrong):

n(pi)= 27
n(1-pi)=27
e(x)=27
var(x)=13.5
stnd dev=3.674

z= (36-27)/3.674 = 2.45

A z of 2.45 = .5-.4929 = a probabilty of .0071 that a 50% bettor would hit 36/54 bets.

Is this correct? Is there less than a 1% chance that what I am doing to determine my bets actually hits 50%?

[FourLengthsClear]

Is this correct? Is there less than a 1% chance that what I am doing to determine my bets actually hits 50%?

Yes, correct.

With that said there is little doubt that this is mostly variance. Using the same methods you have used you will note that the probability of going 36-18 would only be around 13% if you were a 60% handicapper.