Equation for RSI on ROC (Momentum Pinball Indicator)

 

Trying to understand the Momentum Pinball oscillator more - it's a 3 period RSI on a one period rate of change. What would this look like expressed as plain math? Wilder's RSI is this:

RSI = 100 – [100/1 +RS]
RS = Average of n periods closes up/Average of n periods closes down.

Would Momentum Pinball be this?

RSI = 100 – [100/1 +ROC]
ROC 3 period = [(Today's close - Yesterday's close) + (Yesterday's close - Close 2 days ago) + (Close 2 days ago - Close 3 days ago)]/3

Reason: