Ugh. This is why I suggest everyone (a) start off by understanding a balanced count, and (b) really think about the math that goes behind the counts. Focus less on the process (what gets subtracted from what) and focus more on the fundamentals (what does what mean).
The pivot is defined from your initial running count (IRC). Your IRC is completely up to you to choose, which means your pivot can be anything. What is constant is the difference between the pivot and the IRC, which is always Decks*Imbalance. A lot of sites use U for imbalance (so I will too), but it's basically the difference between the number of low cards and the number of high cards in one deck. So for Red 7, U = 2 and the pivot for a 6-deck shoe is 6*2 = 12 higher than the IRC.
Now, where you start the IRC is completely up to you. It can be -12 (in which case the pivot is 0), it can be -10 (in which case the pivot is +2), it can be 0 (in which case the pivot is +12), or it can be +5,142 (in which case the pivot is +5,154).
Often the book advocates a specific IRC - so read BBiBJ carefully to see how Snyder defines his IRC. If I recall correctly, he defines the IRC to be -(Decks-1)*U, or for the example above, -(6-1)*2 = -10. This is done for a specific reason: because mathematically, at the pivot, the true count is equal to +U. That is, if you start your 6-deck Red 7 count at -10, whenever the RUNNING count is +2, the TRUE count is +2 and no deck estimation is needed.
Of course, you're free to start your count wherever you wish, but just remember that at your pivot, the true count is always +U. If you're counting a 13-deck game with a K-O (U = 4) count and an IRC of 69, you just need to remember that at your pivot (+69 + 13*4 = +121), the true count is +4.
Some people like to start the IRC higher so that the running count is always positive (many people have problems doing math with negative numbers). Some people like to start the IRC so that the pivot is 0. Some people like to start the IRC so that the pivot equals +U. Whatever you do, just remember that the pivot is defined from the IRC and the IRC is arbitrary, so read carefully. You are in for a world of hurt if you take advice to raise your bets at a RC of 0 or higher from a site where the IRC is -decks*U, and then mix it with advice from another site to start your IRC at 0.