When I was a kid, my dad use to blast the Celtics for keeping McHale and Parish too long. He'd tell me that if they keep them until they past their prime, their trade value will be nothing. Being a kid, I thought he was stupid because I was being loyal.
Having said that and suffering for nearly 22 years, I say trade Pierce and Allen (in a year or two) and keep a winning team for years to come. 
Times have changed due to the salary cap so overall I do not agree. 
I want Paul to retire a Celtic as long as he's willing to be paid what he is worth. ; 
Ray Allen Will be packaged and traded when he is expiring. 
You see, your falling into the same trap I fell into. I loved Mchale and never wanted to see him in another uniform. So he retires a Celtic and the team is terrible for 15 years. I don't want the same mistakes with Pierce. In the last year of his contract, he has to be traded. It could load this team up for 5 more years depending on who was brought in. Same goes for Ray!!!
I know where your coming from and agree with the essence of your point but I still disagree overall.

The league has changed so much in the last 15 years with the salary cap that trades are no longer based on talent (and I know you know this).
Take a look some superstars that have changed hands the past five years:
- KG to a contender for youth, picks and an expiring contract.
- Jason Kidd to a contender for youth, picks and an expiring contract going to a team out of contention building for the future.
- Pau Gasol to a contender for youth, picks and an expiring contract going to a team out of contention building for the future.
- Shaq to a contender for youth, picks and an expiring contract going to a team out of contention building for the future.
There is a trend that the Celtics and will not fit into with PP is in his final year. Ray Allen will be traded by this time to a team looking for youth, picks and an expiring contract to build for the future, Keep in mind you have still been getting solid MLE's for the last 4 years and when late draft picks getting trained and accelerated by playing with a veteran team.
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