The idea of streaming has been around as long as leagues with daily transactions have been around. The idea is to pick up a pitcher for the day he pitches and drop him the next day in favor of another guy about to throw. This method allows you to rack up more wins and strikeouts, by having an extra pitcher going every day. Though this does make you vulnerable to higher ERA and WHIP due to the fact that these players are on the waiver wire, so they probably aren’t that good to begin with. So why expose yourself to higher ratios? Well, you can usually pick a good matchup against a weak hitting opponent and usually get a good result.
So what’s the problem? Some leagues disapprove of this tactic. Those who frown on it will refer to it as pitch and ditch. They argue that it takes little skill to grab a new pitcher every day and ruins the integrity of the league.
So when do you do it? If you are in a permanent league with people you know, you should avoid it at all costs, unless it is standard practice by other league members. If you are in a league with people you don’t know and you won’t ever be in a league with again, I’d do it in the playoffs only. If you start doing it in the regular season, you’ll show everyone else how to do it and they’ll do it against you. If you wait for the playoffs (when it matters most), you will be able to catch them by surprise and gain an advantage.