slinslin
Welcome to Amareca
Actually you are wrong. Anderson's cap hit is $21 million but his deal was renegotiated to lower the guaranteed amount of salary he receives in the final year of the contract. If he is retained by the Heat for next season then his full $21 million is guaranteed but if he's waived or bought out then only the guaranteed amount of salary is counted against the cap. You are correct in that a player can not renegotiate his contract to create cap space for his team the main takeaway from that is how a player does not have a team if they are waived. So the player, Anderson in this case, agreed that to reduce the amount of guaranteed money on the final year of his contract. If he's retained then he loses nothing but if he's waived he would only received that guaranteed amount and the number that counts against the cap is the guaranteed amount.
See question #60 about other things in contracts that can be renegotiated...
http://www.cbafaq.com/salarycap.htm#Q60
Invalidated by Q59, this is essentially a "pay cut" to increase a teams cap
If what you said was true please answer my question above. Why don't we see teams consistently buy out players to manipulate their cap? We don't because it is not how it works.
Surely a lot of players would be open to that in order to sign a new deal somwhere else and mutually agree to a buyout with a team that would gain capspace from this or luxury tax relief.