As the title says, you will hit a homerun except if you hit it foul. It is better to do it in practice mode because you need full stars. Okay when you go at bat don't move because luigi will pitch it straight down the middle. Charge up holding down R. Then just like using a special swing release the bat at the right time and you will hit a very far homerun. To make sure you do this correctly before the bal goes off the bat some star will appear on the right of your bat. This cheat is awesome you should try it.
Added by: LugiaMaster101 Dec 21st 2006, ID#7167