This is yet another post about "why don't my by-hand calculations match CVCX output." I have read many of them and done my do diligence but still want to understand the underlying math.

I am using the formula from Blackjack Attack 3 on page 20-21 to calculate per hand standard deviation, but it does not match when I use simulations for multiple hands. According to BJA3

SD = TC_FREQ * TC_BET^2 * TC_SPOTS * (TC_SD^2 * TC_SPOTS + 0.5 * TC_SPOTS * (TC_SPOTS - 1))

... for each simulated true count, where TC_* is the simulation/entered value for that given true count.

But when I run the numbers, I get different results. Am I missing something?