[ QUOTE ]
Let's look at two players. Both have the same number of "big" pots and all are of equal size. However, Player A has 65% of his big pots positive while Player B has just 35% of his big pots positive. Both will have roughly the same SD.
[/ QUOTE ]
I don't see how this is a problem since expected win rate is also part of the calculation. As such, Player A's ROR is much lower than Player B's.
[ QUOTE ]
On another point, standard winrate analysis takes too much into account all the pots the player does not win or lose much on, i.e. most pots (99% or more).
[/ QUOTE ]
Not as much as you seem to think. The only real effect these have on the SD is by adding hands in the denominator. Their effect is on the frequency of big pots. I admit that the SD does not obviously balance these two effects particularly well. But it isn't obvious that it does a terrible job either.
For now, here's a peek at a frequency histogram of my last 25k PLO 50 hands. I didn't run all that well and only showed about a 1.5 ptBB/100 hands (Boo).
Each column represents a range of +/- $2.5 around the value on the x-axis. BTW, since the top of the graph is cut off. The central column at $0 (-2.5 to +2.5) represents almost 22k of the 25k hands.
Someday, I'd like to do a Monte Carlo simulation with this data to test how reasonable the normal approximation is for bankroll estimation.