He just needs more in-game practice with his jumper...and unfortunately, he hasn't been getting any in-game practice lately. Each of the games this month, we've been emphasizing getting the Big 3 going, trying to play like we've been playing in the Championship season.
Like a lot of people have said - just look at the HORSE game, it's not like he can't shoot. I think once Rondo gets to the point where he knows it's ok to shoot when he's open, that it's ok to not have to look for Ray/KG/Paul for options 1/2/3, he'll be more confident in his jumper.
I wish we got him more opportunities to shoot jumpers in games, and not just last-second shots when he has no choice.
I'm hoping Rondo's 70%+ free throw shooting continues into the playoffs. Has anyone noticed him practicing free throws during pregame introductions? It's pretty clever actually... the lights are flashing in the Garden, it's crazy noisy, and the crowd even starts booing when the opponents are introduced - it's just like a playoff atmosphere!