What do the colors mean? I assume this is complete passes only, not intercepted ones? How about displaying some heatmap of passes instead of individual vectors for a different view? Have you considered denoting the direction of the pass with a dot for the start/end or an arrow if not too busy? Is there any indication of the speed of the pass? How about summary stats for each player, team, etc? # of passes, average speed, % complete, how concentrated vs. distributed they are over the squad, which players receive the ball most/least often, which players receive the ball from most players/fewer players, same for positions (individually or grouped by defenders/midfielders/attackers)

OK, I'll stop brainstorming :-) Cool visualization!