BK,

TC = RC / #remaining decks

Suppose you Insurance index is 3 and there is 2.5 decks left. You'r running count is 8.

8/2.5 = 3.2, so you take insurance.

Another way is: TC x #remaing decks = RC

Since when the TC = index you make the strategy deviation:

Index x #remaing decks = RC

So, 3 x 2.5 = 7.5

Since your running count is greater than 7.5 you take insurance.

In summary, multiply your Index for the play by #remaing decks. This gives you the RC needed to make the strategy deviation.

One more example. You have 12 and dealer has 6 up. Suppose your index for this is -8. The RC is -15. There is 1.75 decks left to be dealt.

1.75 x -8 = -14

Since -15, the running count is less than -14 you hit.

Bert