I know, everyone and their mother has made a RC formula or two. I was just messing around in some huge spreadsheet quite a while ago and kinda just stumbled across this. The thing that started me messing around is that I don't like complicated equations and OPS is nice because its so simple and uses numbers I already have a good sense for.
As we all know OPS is a decent judge of runs created but it isn't as good as we would like. We also know it undervalues OBP.
OPS = OBP + SLG = (AVG + ISOpa) + (AVG + ISOpo) = 2*AVG + ISOpa + ISOpo
So my idea was basically to take a bunch of data and fit the expression RC/PA = a*AVG + b*ISOpa + c*ISOpo and do a pretty straightforward regression. This actually gave pretty good results. RC/PA = 7.674*AVG + 6.357*ISOpa + 14.945*ISOpo but the R^2 was only 0.8 which isn't very good when compared against team RS results from the past 40 years. After looking at some of the residuals it was apparent that it was too simple to represent the AVG term as just a single order term.
To improve it I changed it to RC/PA = a*AVG + b*AVG^2 + c*ISOpa + d*ISOpo. I know this is getting away from the simplicity and that made me sad. This gave great results though. RC/PA = 1.4088*AVG^2 - 0.1412*AVG + 0.3446*ISOpa + 0.2701*ISOpo and has a R^2 of 0.96 when compared against team RS results. Also, when compared against Baseruns it has an R^2 of 0.999 which basically means that it gives you baseruns without the complex formula that baseruns has.
I like it. I don't know if I'll use it. I just thought it was surprising that it did so well when compared against something as advanced as Baseruns.
Oh, I looked at including things like SB or CS but when using team RS to create a correlation the impact of SB and CS is just not significant and gives pretty strange results sometimes.