Of course you can still lose. 98% chance of winning means 2% chance of losing. If the odds are accurate - and there's no reason to think they are not - then after enough iterations the number of wins versus losses will be 98/2. Flip a coin...odds of heads is 50%. Flip a second time...odds of heads still 50%. It's certainly possible of flipping heads twice (odds 25%) which makes tails callers upset because they thought they had a 50% chance of winning. Flip 1000 times and the split will be 50:50 or within a fraction of a percentage point. Same thing with your 98% example. Might lose a couple of times in a couple of tries...try 20 times and your wins will accumulate. Simple math.