New York ? Major League Baseball reversed its long-standing opposition to instant replay and will allow umpires to check video on home-run calls in series that start Thursday.

The start date comes nearly 10 months after general managers voted 25-5 to use the technology, and following MLB agreements with the unions for umpires and for players.

“I believe that the extraordinary technology that we now have merits the use of instant replay on a very limited basis,” commissioner Bud Selig said. “The system we have in place will ensure that the proper call is made on home run balls and will not cause a significant delay to the game.”

Three series are scheduled to start Thursday, with Philadelphia at the Chicago Cubs, Minnesota at Oakland and Texas at the Los Angeles Angels. For other games, replays will be available to umpires starting Friday.

For now, video will be used only on so-called “boundary calls,” such as determining whether fly balls went over the fence, whether potential home runs were fair or foul and whether there was fan interference on potential home runs.