You can't really "blow the chance" of getting a rayquaza since you can't get it in-game.
every 1000th wild Pokemon you meet is a shiny, so 1/1000.
You Can Only get A Black One if It's Shiny. Other Than That You Can't And There Is A VERY thin chance of getting one.
Yes you can! You can get a friend bow , Train your Pokemon to Lev. 100, go find articuno ,cross your fingers and defeat Articuno. That is your highest chance of getting legendary Pokemon.
If you battled Rayquaza and defeated it, then it's gone. You only get 1 chance to catch a legendary Pokemon.
If Rayquaza flee'd from the Sky Pillar in Ruby/Sapphire there is no way to get another chance to fight him.
You can trade it from Pokemon Emerald. In Pokemon Emerald, when you find Rayquaza, there is a small chance that it is shiny when you find it. Save the game right before you fight him and keep trying until it turns black. Then catch it and trade it to Pokemon Diamond.
You capture Rayquaza only after that cutscene..after the three legyendaries fight in sootopolis,U have to come back to skypillar and have to capture Rayquaza..in case you lost that chance by making the Pokemon faint or fleeing the battle..you can always use gameshark codes to get Pokemon in the wild.
you know how to catch a rayquaza at sky pillar then you have to try atleast 8,192 times because the chance of getting a shiny is 1 out of 8,192
then you will not get him. if he defeated you or if you defeated him without catching him than you do not have any other chance of getting him unless maybe you trade with another player. well aren't your Pokemon supposed to fade or something?
In the 2nd generation games (Gold/Silver/Crystal), the offspring will have a 1/64 chance of being shiny. In later generation games, the chance of getting a shiny offspring is the same as encountering a wild shiny Pokemon.
No...unless you defeated the Latios...
It raises the chance of getting a shiny from 1 in 8,192 to 1 in 2,048.