Variance
The natural ups and downs in results even when your process is correct. Like flipping a coin 10 times - you might get 8 heads or 3 heads, both are normal variance.
Like getting 8 heads in 10 coin flips. Unusual, but totally normal randomness.
Why it matters
Variance explains why good bettors have losing streaks. Understanding this prevents panic-quitting a winning strategy.
How DMP uses this
Understanding variance helps you trust the process during downswings.
Common mistake
Changing strategy after a losing streak caused by normal variance.