1970 March

11th  Experimental, lively X-5 baseballs are used in all spring training games played in Arizona and Florida. The results are inconclusive.

19th  In Arizona, the Indians lose slugger Ken Harrelson when he breaks his right ankle sliding into 2B. He will be sidelined until September.

24th  Commissioner Kuhn orders a halt to the use of X-5 balls.