For two sports that seem so diametrically opposed, soccer and basketball might be the most similar overall. Consider that in one most ball handling is by hand and it is an infraction to apply the feet; while in the other most ball movement is by foot and it is penalty to touch the ball with your hand. That contrast is true for shooting, passing, and defending (except for the goal keeper in soccer). So why am I putting them forward as the most similar sports?
While the ball manipulation takes place at opposite ends of the body, almost every thing about the strategy, tactics, and flow of the games are similar if not exactly the same.