Because of the way it calculates catch rates, the masterball has a 1 in 65536 chance of failing.
Wait, since the DS numbers can only go up to 65535, how does it have a 1 in 65536 chance of failing?
Divide that by ten-thousand and it's close to the French Franc-to-Euro exchange rate from the 2002 currency switchover (6.55957)
Don't ask me why I remember that