asking hypers reg or even turbo regs
lets say your ROI overall is around 8% vs a certain player

whats your win % if you got them outchipped them like 3-1 in chips
how much more than 75% is it?

I'm going to make the assumption you are 8% at that X stack size for the purpose of this calculation
I'm trying to calculate this maths

Need to know this to use for MTT deals in HU

I have an approach using what I call a Player Capability Index (PCI), that adjusts the ICM equal capability assumption for varying player capability. The adjustment is made by multiplying the players stack size by the index.

If 2 players are of equal capability in a 10-1 SNG their ROI would be -1/11 = -9%. You say you have an 8% ROI. The PCI equivalent to that is 1.45 determined by finding the stack size increase factor to yield 8%.

Now you assumed a 75 to 25 stack advantage so your ROI assuming equal capability is (0.75*20 – 11)/11 =0.36

Now we multiply the stack size of 75 by the PCI of 1.45 to account for your higher capability and your ROI increases to 48%. The win percentage increases to 81%.

As far as I know, this approach is novel and I would think there are other approaches that may be more conventional.