The Irish (Chicago) gambit is extremely rare and occurs in less than 1 in 10,000 games. From the data, you can expect that White will have a 50.0% chance of winning, while Black should have a 50.0% chance of winning. Even though most players have probably never seen this opening, (so you can catch them off guard), the edge that White has is small (less than 2%). So it is probably not worth it to study this variation since as Black, the edge you gain isn't that great.