All players with a career average of 20 ppg or more and 6'10" or taller
There were 13 players on the list including Bosh and Amar'e. Of the 13 only Moses Malone and Hakeem showed a significant improvement in their ppg for the rest of his career after their fourth season.
1. Wilt had his best scoring season in his 3rd year in the league when he averaged 50.4 ppg
2. Kareem had his best scoring season in his 3rd year in the league when averaged 34.8 ppg
If you can find two better big men scorers in the history of the NBA let us all know. Thanks
3. Dirk has his best scoring year in his 8th season but it was only 3 ppg more than he scored in his third season. Bargnani averaged 15.4 ppg in his third season, so even if he duplicates Dirk then his best season will only be at around 18.5 ppg.
4. Pat Ewing -5th but after that he never again came within 4 ppg of his average in his 5th season. He also never again exceeded his ppg in his fourth season by more than 2 ppg.
5 M. Malone - 8th
6. Shaq - 8th but it was only .4 ppg more than he averaged in 2nd and 3rd seasons
7. D. Robinson - 5th but he only came within 5 ppg of his ave in his 5th season one other season. His career average was 2 ppg less than what he averaged in his 4th season
8. Hakeem - 11th however, in his 5th season his ppg was only about 1.5 above what he averaged in this prior 3 season.
9. Duncan - 5th but it was only about 3 ppg more than his average over his first four seasons and he never came again has come within 2 ppg of his ppg in his his 5th season
10. Walt Bellamy - 1st season averaged over 31 ppg and never came near that number again
11 .Bob Lanier - 2nd season
12. Amar'e - 3rd season
13. Bosh - 7th season but only 1.5 ppg more than he averaged in his 3rd and 4th seasons.
So of the 13 only Mose Malone and Hakeem showed consistent significant improvement in their scoring over the rest of their career as compared to their 4th season even though a number of them did have a single career scoring season after their 4th season
Doesn't seem like historical odds are in Bargnani's favor in becoming a big time scorer.