Simply to clarify
toolyp said
at least” is a favourite of mine too. There is a formula for that too. The probability of heads/tails is 0.5 or 1 in 2. Based on your reasoning, we toss 2 times and get heads. Nope. The chance to get heads in 2 tosses is 0.75. The chance to get heads in 4 tosses is 95%. The chance to get heads in 7 tosses is 99%. The chance to get heads in 10 tosses is 99.9%.
The probability of winning x in a row is y - the probability of winning any of the then present tosses is .5 or 2-1 or 50%. Now as for streaks, I can provide additional examples as those already displayed.