Measuring churn

I've mentioned the concept of churn before, in the context of consecutive sessions. The concept also applies on a more micro level; a single session can exhibit churn, when you look at the individual hand deltas within it. I've struggled off and on to come up with a formula for measuring churn. I came up with one a while ago, but only now have started to believe that it has some merit. Here's the formula:

churn = (the sum of the absolute values of the individual hand deltas) /  (the sum of the individual hand deltas)

Of course, the denominator is what I've been calling the session delta. Since you need the full hand history of the session in order to be able to calculate churn, I can't calculate it for the sessions which predate my use of the automatic history saving feature of the PokerStars client software.

Last night, I had a big churn number: 157850 / 6150, or 25.67. Any number over 10 indicates a significant amount of churn.

During current Hold'em session you were dealt 110 hands and saw flop:
 - 22 out of 23 times while in big blind (95%)
 - 16 out of 22 times while in small blind (72%)
 - 46 out of 65 times in other positions (70%)
 - a total of 84 out of 110 (76%)
 Pots won at showdown - 9 of 28 (32%)
 Pots won without showdown - 13

delta: $6,150
balance: $4,543,994