Yes Kareem's skillset didn't change, but his results were a lot better
Kareem scored 36 per 100 possession in the 80 playoffs versus 29 in 79, thats a huge increase, while still being pretty efficient
He had a different role in 1979 team though. Besides, he had better defensive and passing season, which you don't take into account. 1980 and 1979 are extremely close, no matter what would you look at.
In 71 playoffs, The league shot 45% fg, WIlt shot 49% scoring 22 a game against the best defense and 3rd (?) best defender in the league. That's not good to say the least?
It's not good, because on average players also shot far better from FT line than Wilt. Wilt had to score better from the field to remain efficient. He was still below average in TS% than playoffs average (48.8% vs 49.0%).
22 ppg on league average efficiency doesn't make you a strong, capable first option. It shows that Wilt still could score when needed, but he couldn't be the first option.
77 Walton was 50%, 19 ppg, 74 Cowens was 44%, 22.7 ppg,
1. 1977 Walton shot better from FT line, which made him better overall scorer - 52.7 TS% is better than 48.8 TS%, even adjusting to league average.
2. Dave Cowens certainly wasn't a good scorer, so I don't see your point.
The simple fact that you compare Wilt to Walton and Cowens, who are not known for being good scorers, proves my point. Wilt wasn't elite scorer anymore in 1971 and he couldn't carry the offense.
