The 'Big 3' to stop this Sunday will be KG, PP, and Rondo. Wally has been outplaying Allen all series (!) and I find it hard to believe it will change in game 7. The Cavs may be able to sustain good outings by KG and PP, but Rondo will put them over the top. Rondo has played a big part in almost every win, while his ineffectiveness (turnovers, few points) left the Celts' in a bad position in game 6. Delonte needs to have his best defensive game Sunday.
Relying on rondo is like relying on rafer. They will have good games and some bad games, but not very consistently.