The problem about sports bettors is how big the bets are after some time, i call that a snow ball because in sports the way to make huge money is by betting almost all our bankroll on a "Secure" event, and most times we will end up with profit but we only need one bad bet to see it all gone.
Winning little amount can actually come in a short term when you bets on less risk games with poor odds and little amount of wagers.
That is if you are not a risk taker or you are not chasing big wins.
But if you must win big, then you must have to face the risk which would either be you bet of higher odds or you stake with huge amount of wagers.
Then once the winning comes, it comes big but then since winning in a short term may not be guaranteed, you will need to keep betting on a long time which may require you stocking your bankroll hugely in order to serve you for a long time.
Whichever way, huge requires enough funds so that if you don't win in the Short while, a long while may probably give you a better chance to win.