Just over half ball/strike challenges successful on first day of spring training games

Just over half the ball/strike challenges were successful on the first day of spring training games Friday as Major League Baseball prepared for the first regular-season use of the automated ball-strike system — the so-called robot umpires.

Thirteen of 23 calls were overturned during the five games, MLB said, which came to 56.5%.

There were an average of 4.6 challenges per game and 2.6 overturned calls per game.

Seven challenges were made of plate umpire Alex MacKay’s calls during Arizona’s 3-2 win over Colorado...