VaSpursFan made the most poignant point to me. Finley doesn't have confidence. The very best shooters with no confidence will fail more times than not, especially in games with the pressure on.
Finley has always been a set shot jump shooter. And, he used to have the most rigorous and meticulous off-season conditioning and jump-shooting programs. I have a few friends that used to train in Chicago at the same gym. They said he worked on his jumper everyday in the summer, six days a week, like crazy.
In the past few years, especially with some of the injuries he's had, he doesn't go through the same rigorous program, not only in the off-season, but during the season as well.