Any time you sign a player to a contract that includes a bonus, the bonus money can't ever come off your cap. The total bonus is prorated over the length of the contract (i.e. a $10 million bonus over a 5 year contract counts as $2 million against the cap each year). As long as you have the player, it's just part of his contract and is counted as such (i.e. current season's cap hit = season salary + season prorate of bonus).
If you cut a player, any remaining prorate of the bonus becomes dead cap and "accelerates" as follows:
- The cap hit of the bonus for the current year remains the same.
- The cap hit of any remaining years after the current year all hit next year.
Example:
$10 million bonus, 5 year deal. Original cap hits for bonus:
Year 1: $2 million
Year 2: $2 million
Year 3: $2 million
Year 4: $2 million
Year 5: $2 million
Let's say the player is cut during year 2. The cap hit is now:
Year 1: $2 million
Year 2: $2 million
Year 3: $6 million
Year 4: $0
Year 5: $0
Hope that makes sense.
As to your original point, yes, having $0 dead cap for next year is great. It basically means you didn't cut anyone with remaining bonus this year.