Any fantasy football player knows that Lesean McCoy is a stud. However, if it costs you a first-round pick every year to keep someone like McCoy, eventually the cost catches up with that owner.

You have to remember that most keeper leagues involve some type of trade-off in terms of value. Traditionally, you'll have to forfeit a specific pick when keeping a player. Or, in an auction, you'll have to pay the price you did in the season prior.

The key here is to try and find the difference in value between the current average draft position (ADP) of a player on your roster and the slot in which you'll have to lose in order to keep that player. For instance, if you have Keenan Allen and snagged him on the waiver wire last year, and you lose a late-round pick, you'll almost always want to keep him. However, if you have to use a third-round pick to keep Allen, you have to think long and hard, as that's essentially his average draft cost.