HOW TO DO IT

This will make it real easy If the first card, for instances, is a little card,{+1} and the Second a Jack a big card,{-2} the running count is {-1}. And so it goes all the way through the deck so when the Insurance count eclipses {+4}, we have the information that the probability that the hidden dealer's card is greater than the 2 to 1 Payoff of the bet, hence it's a good bet.

The insurance count is this number and it changes as the deck/shoe depletes itself, If the Player's got a good deck, that is won, It is likely that because the Tens came out, favoring the player's that one would expect the insurance count to be negative. Hence you would be disinclined to take the Insurance Bet. Just remember the Tens count as -2. A through 9 +1.

As in any Counting System, you must change form the Basic Strategy to win money. The Same is true here. The change in strategy in this instance is to take the insurance bet.