I was browsing the player statistics on AFL Tables and I found this one:

James Jordon has the highest winning percentage of any current AFL player who has played 50 games or more (53 wins, 1 draw, 17 losses, 75.35%, 1st). The other Swans player in the top 20 on this list is Logan McDonald (33 wins, 1 draw, 16 losses, 67.00%, 18th).

I was looking at this after the AFL website was roasting North Melbourne for having several players with low career winning percentages. Bailey Scott (NM) has the lowest winning percentage of current players who have played 50 games or more: 9 wins, 1 draw, 74 losses, 11.31%.