"Tonight will be Big Three Lite's truest Celtics moment.

Certainly the world championship run three years ago of Paul Pierce, Ray Allen and Kevin Garnett will allow them to live on in the hearts and memories of Celts fans, but, truth be told, they have achieved less than what was anticipated when they first arrived for an assortment of reasons, not all of their own making.

Regardless of why they failed to hold a 13-point second-half lead last year in Game 7 of the NBA Finals against the Lakers, that loss, in some ways, begat what has happened to them since. Big Three Lite seemed to wither and grow old that day, a circumstance that seldom reverses itself in sports.

This season its fade has continued to the point where tonight it faces elimination in the Eastern Conference semifinals at the hands of a team built in its own image. The Miami Heat are not so much a team as a concoction, the joining of three players from far-flung ports to form a unit capable of winning an NBA championship without following the usual building process.

The Heat have their own Big Three, and it is far from lite. It is made up of three guys who are younger, faster, stronger and perhaps even hungrier than the Celtics' aging version, which is all the more reason why what happens tonight at American Airlines [AMR] Arena is so significant to the legacy of Pierce, Allen and Garnett in Boston.

It seems foolish to suggest that somehow the aging and infirm team Danny Ainge put together this season will win three straight from the Heat, two of them in Miami, and thus advance to the East finals. Anything is possible, but some things are more unlikely than others, and at the moment a sighting of Halley's comet seems more likely than a sighting of Banner 18 in the Garden rafters."