Forex No Scale Down Risk of Ruin

Hi all,
does anyone know any way to count risk of ruin but when in drawdown the position size used for trading isn't scaled down
(I can only found the scaled down ones)
for example I have 10,000$ account, my risk is 20 pips per trade,
winrate is 40% for 3-4R, risk per trade is 2% so per trade my position size is 1000$, Ruin is 50% drawdown
Let's say I get 10% drawdown (capital now 9000$) instead of scaling down my position to 900$ per trade, I still use 1000$
the same when I get 20% gain (capital now 12000$) I will use 1200$ and when I get 10% drawdown I will still use 1200$ per trade
not safe I know, currently playing around with MM

appreciate your help

Regards, Dan

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