Some time ago, Prof. Berri published a story on the effect on WP48 of changing from one team to another. The piece focused on Al Jefferson moving from to Utah from Minnesota. That piece is here. In it the effect is given as:
-.300 ( Avg WP48 of New Teammates -Avg WP48 of Old Teammates)
Since this seems to be causing some confusion I did a quick table:
Players moving from good to bad teams see their numbers improve slightly, Players moving from bad to good teams see their numbers get slightly worse. This table only applies to the player moving though.
So for example, Jefferson would be expected to get slightly worse from going to Utah (as would Matt Barnes going to LA). Alternatively, Michael Beasley would be expected to improve going to Minnesota (interestingly so would Amare which hasn’t really happened).
A player moving from teams that are roughly the same in terms of wp48 (say Shaq or Boozer) would not see any significant impact.
Ok. Happy Thanksgiving!