Tanking Solution

As soon as a team is eliminated from playoff contention they are assigned lottery odds based on number of wins from that point.

So Team A is eliminated with 25 games to go, Team B with 20 and Team C with 15. A has 25 games to secure the best lottery odds, so the worst team still has the best chance to get the most wins, and therefore the best lottery odds. However a straight tank isn't going to work because 5 games isn't enough of a cushion over B, and a very motivated C might even catch them. Now you'll have Lottery teams still trying to be competitive with those seeking better seeds.