chalk,
That is the conventional wisdom, but I know for a fact it's not true.
I have a MLB model I've used the past 1.5 seasons. I bet strictly on the moneyline, and each bet is 1 unit. I play around 95% of the games. And I've made great returns on it each year.
I suppose college basketball could be different. I am admittedly a rookie when it comes to serious college basketball betting. Maybe you can't make many plays and I will lose. Or maybe my system will just flat suck.
What I do know is that through 225 games (that's 450 possible positions), my system has advocated taking 214 positions. And currently the system is up 19.38 units on sides and 37.64 units on totals. Now that could just be luck, but for now I'm sticking with it.