Here are the plays that have been changed due to instant replay.
5/13 Cardinals @ Pirates
In the bottom of the first, Adam LaRoche hit a ball to right that hit either a railing or a screen above the 21-foot wall. Both objects are in play but first base umpire Lance Barksdale ruled it a home run. LaRoche had stopped at second but continued on to score. After crew chief Randy Marsh and two other members of the crew watched the replay, Marsh reversed the call from homer to in play and awarded LaRoche a double. This was the first homer that was reviewed and reversed.
5/13 Marlins @ Brewers
About two and a half hours after the LeRoche review, Ross Gload of the Marlins hit a ball in the top of the sixth in Milwaukee into the right field corner. The ball cleared the 8-foot wall and was ruled a homer by first base umpire Bruce Dreckman. The Brewers complained about the call. Crew chief Gary Darling took about two minutes to watch the replay and reversed the call from homer to foul.
5/23 Mets @ Red Sox
Mets catcher Omir Santos hit the ball to the top of the LF wall at Fenway Park and it was called in play by 3B umpire Paul Nauert. The umpires watch the replay and crew chief Joe West reversed the call to a home run. The hit came off Red Sox closer Jonathan Papelbon and turned a 2-1 deficit into a 3-2 victory for the Mets.
5/27 Nationals @ Mets
For the second time in the series and fourth time in five days for the Mets, a replay was used. With the game tied 3-3 in the bottom of the sixth inning, Daniel Murphy of the Mets hit a fly ball that struck a yellow advertising sign on the faηade of the second deck. Nationals RF Adam Dunn picked up the ball on the warning track and started a relay that threw out Gary Sheffield at the plate. However, acting crew chief Larry Vanover (in the absence of chief Charlie Reliford) watched a replay and reversed the call to a home run. There was a four-minute delay for the replay.
6/6 Rangers @ Red Sox
Mike Lowell hit a fly ball down the LF line in the bottom of second inning that hit just over the wall off the facing of the first row of Monster Seats. The ball was ruled in play by 3B umpire (and acting crew chief) Jeff Kellogg. After, a discussion with 3B coach DeMarlo Hale and manager Terry Francona, Kellogg watched the replay and reversed the call to a home run.
6/9 Mariners @ Orioles
Endy Chavez jumped in an attempt to catch Melvin Mora's fly at the wall in LF in the bottom of the first inning. A fan touched the ball and the play was ruled a home run. The Mariners objected to the call, so crew chief Gary Cederstrom watched the replay. The call was overturned from a home run to an out because the fan interfered with Chavez's chance to catch the ball.
6/19 Brewers @ Tigers
In the bottom of the third inning, Miguel Cabrera's hit went over the top of the fence, hit the roof of the bullpen dugout and came back on the field. It was ruled in play but the Tigers argued the call so crew chief Dale Scott looked at the replay and overturned the call to a home run.
6/19 Brewers @ Tigers
For the first time, two calls were reviewed in the same game. Dusty Ryan's line drive down the LF line in the bottom of the fourth was ruled a home run. Brewers manager Ken Macha objected to the call, so crew chief Dale Scott watched the replay and reversed the call to in play, awarding Ryan a double.
7/3 Astros @ Giants
In the bottom of the second inning, Travis Ishikawa's fly ball to right center hit at the top of the wall and was ruled in play for a double. Giants manager Bruce Bochy talked to crew chief and plate umpire Randy Marsh about the play; the umpires huddled and then watched the replay. The play was reversed to a home run for Ishikawa since the ball hit the protective railing on top of the wall.
7/19 Twins @ Rangers
In the bottom of the fourth inning, Andruw Jones hit a fly ball down the left field line that was called a home run. Twins manager Ron Gardenhire immediately came out to talk with 3B umpire Brian ONora. ONora went to crew chief (and plate umpire) Gary Cederstrom to talk. Cederstrom watched the replay and reversed the call to a foul ball.
7/22 Brewers @ Pirates
In the bottom of the third inning, Ryan Doumit's fly ball to right was touched by a fan and was ruled in play. Acting crew chief Wally Bell watched the replay and reversed the call to a home run. Three of four consecutive batters homered for the Pirates.
7/29 Nationals @ Brewers
In the bottom of the third inning, Ryan Braun's fly to deep CF hit the glove of Nationals centerfielder Nyjer Morgan. It then went behind the glove, striking the yellow stripe at the top of the wall. The it was ruled a home run; the umpires huddled and then crew chief Joe West watched the replay and reversed the call to ball in play. West ruled that Counsell scored and Braun was at third.
8/11 Phillies @ Cubs
In the top of the ninth, a fly ball by Carlos Ruiz down the LF line was called fair and a home run. Crew chief (and 3B umpire) Dale Scott huddled with the crew and then watched the replay. Scott reversed the call to a foul ball.
8/16 Astros @ Brewers
In the top of the sixth inning, Geoff Blum hit a three-run homer to right. Astros right fielder Hunter Pence followed with a fly ball down the LF line that was ruled fair and a home run. Crew chief Tim Welke looked at the replay and overturned the call to a foul ball.
8/31 Pirates @ Reds
In the bottom of the fifth inning of the second game of a double header, Brandon Phillips hit a towering fly ball down the left field line. It was ruled a home run by third base umpire Dan Iassogna but Pirates manager John Russell objected to the call. Crew chief Rick Reed watched the replay and overturned the call to a foul ball. It took less than two minutes for the replay. Phillips had homered previously in the game.
9/5 Yankees @ Blue Jays
In the bottom of the second inning, Randy Ruiz hit a drive down the left field line that appeared to have bounced off the foul pole and back onto the field for a home run, which was the ruling by third base umpire Jeff Nelson. Led by crew chief Tim Tschida, the examination of the replay showed the ball hit the blue facing just to the left of the mesh of the foul pole, so it was ruled a foul ball. Ruiz then grounded out, but homered in the fourth into left-center, nowhere near the pole.
9/12 Mariners @ Rangers
A fly ball to left center by Chris Davis to lead off the bottom of the fifth inning was ruled a home run. Seattle manager Don Wakamatsu asked about the call so crew chief Gary Cederstrom watched the replay and overturned the call to a ball in play. Davis was awarded second base.
9/22 Giants @ Diamondbacks
In the bottom of the third inning, Gerardo Parra hit a fly ball which struck the chain link portion of the fence in the deepest part of right center field. First base umpire Marty Foster called the ball a home run but the umpires immediately gathered in the infield. Acting crew chief Wally Bell watched the replay and overturned the call to a ball in play. He awarded Parra a double and allowed the runner from first, Miguel Montero, to score.
9/29 Diamondbacks @ Giants
In the top of the fourth inning, immediately after a home run by Miguel Montero, Ryan Roberts hit a fly ball to LF that Andres Torres jumped for and caught over the top of the wall. The ball flew up out of the glove as Torres started back to the ground, hit the top of the wall and bounced back onto the field, where Torres, while lying on the ground, caught. Since the ball did not go over the fence, it was still in play. Since it hit the fence it was not a catch. The play was ruled a homer at first but crew chief Dana DeMuth watched the replay and overturned it to a double.
9/30 Astros @ Phillies
In the top of the second inning, J.R. Towles fly ball landed in the flower beds in left center and bounced back onto the field; It was ruled in play. Astros acting manager Dave Clark asked about the call so crew chief Tim Tschida watched the replay and overturned his own call to a home run.
10/31 Yankees @ Phillies (World Series)
In the top of the fourth inning, Alex Rodriguez hit a fly ball down the right field line that hit just inside the pole. The ball struck a television camera and was called in play by RF umpire Jeff Nelson. Yankees manager Joe Girardi asked about the call, so crew chief Gerry Davis and three of the other five umpires watched the replay and overturned the call to a home run. This was the first use of replay in postseason.
Replay instances without the call being changed
Use of Replay in the Wrong Situation
On June 25, 2009, the Phillies were playing in St. Petersburg against the Rays. In the bottom of the seventh inning, Pat Burrell came to the plate with a runner on first and two outs. He hit a fly ball which bounced into the left-centerfield seats. Crew chief Gary Cederstrom watched a replay to determine if there was fan interference as the ball was leaving the field. After a 1:36 delay, he said that the ball went into the seats cleanly and sent Carl Crawford, who had scored on the play, back to third. MLB Vice President Mike Port told Cederstrom the next day that he was not allowed to use replay in that circumstance.