Ah, I was working on 32 matches. On 64 matches it's insanely bigger! 1 in 3400000000000000000000000000000! Boooooooom!
It's 3 to the power of 64 to my mind. So 3x3x3 etc onwards to 64 times. That is if you assume win, draw and loss are all a 1 in 3 chance, which of course they aren't, but there will be upsets. Even if you say the average odds were 4/5, ie 1.8, the chances are 21,700,000,000,000,000. In truth, it aint happening.
It's like you betting on a given numbver on roulette, a single number, and winning. Then you let it ride another 10 times on seven and it lands every time!