The Magnus effect is something you can see very often in many sports such as soccer, golf, tennis, baseball and so on. In soccer people can do things like curve the ball around a wall of people to get the ball into the net or give the ball backspin to stay in the air a little longer. Many athletes use these outcomes to their advantage while playing. ​

So using the Bernoulli's equation: if the density of the fluid, such as air is the same, as well as the gravity and height. We see that all of the air on the top of the ball is moving in the same direction and on the bottom the outside airflow and the airflow of the ball cancel out. So, the velocity on the top of the ball in this case is higher than the velocity under the ball which then the wind on the top of the ball must have less pressure than the bottom. ​

If there is top spin or clockwise the Magnus force will be pointed down, if there is a counter clockwise spin the magnus force will be pointed up. The ball will move or curve in the direction of the accelerated airflow, it is also the same direction that that ball is spinning towards. ​

A short clip to visualize the Magnus effect from
​https://gfycat.com/gifs/search/magnus+effect