Here is an example I like to give about how hard beating even -110 is and how the accumulation of juice is a mofo.
Lets say you make 10 $100 (1 unit) bets in a week and
go 6-4 win 600 lose 440= $160 win for the week
go 4-6 win 400 and lose 660=$260 loss for week
So if you are alternating 6-4 and 4-6 weeks you are hitting 50/50 but will still lose a unit every 2 weeks