Increase step size/co-efficient after certain number of trades or DD

At times it may happen that the pair moves without any correction and may result in drastic increase of DD, especially in the zone of breakouts.

So if we can increase the distance between trades or lot co-efficient, we will be to control the DD.

I observed that for EURUSD, we can have 15 trades in one direction, with step size 8 & 10 trades in Gold with step size of 500.

So after these number of trades, if we can have step sizes of 12 & 1000 respectively, it will be very helpful. 

Or it can even be linked to amount of DD taken by that magic number (not % of balance as we are going with fixed lot in Grid set. Also it may happen that we may be trading multiple pairs in the same account). 

Say for example, if DD is more than 1500$, the step size to be increased to 12 & 1000 for EURUSD & Gold respectively. However these numbers can be optimized further. :)

Thanks.