Backyard Baseball cheats and cheat codes for Gamecube

Unlock Abner Dubbleplay as player:
Earn all 20 certificates

Unlock Barry Deejay:
Have a saved file from Backyard Basketball on your memory card.

Unlock Derek Jeter:
Execute 2 double plays in a single game in season mode.

Unlock Greg Maddux:
Win 20 games in season mode. Note: Try playing a 32 game season.

Unlock Mike Piazza:
Hit a grand slam in season mode.

Unlock Mr Clanky:
Complete Clanky's Coaching Box.

Unlock Pedro Martinez:
Throw a shutout in season mode.

Unlock Randy Johnson:
Get 75 career strikeouts, which includes the playoffs.

Unlock Shawn Green:
Hit the ball to gain a base 60 times in season mode. 

Unlock Aquadome stadium:
Hit a homerun into the pool at Steele Stadium, into the swamp at 
Gator Flats, and into the lake at Frasier Field.

Certificate list:
Requied certificates to unlock Abner Dubbleplay:

3 Homerun Game
Grand Slam
Hit The Cycle
10 Strikeout Game
3 Stolen Base Game
Winning Pitcher
Threw A No Hitter
Threw A Shutout
5 RBI Game
MVP Of Game
10 Career Hits
30 Career Hits
80 Career Hits
5 Career Homeruns
15 Career Homeruns
30 Career Homeruns
25 Strikeouts
75 Strikeouts
150 Strikeouts
10 Pitching Wins
20 Pitching Wins
30 Pitching Wins
10 Stolen Bases
25 Stolen Bases
50 Stolen Bases