Keeper and dynasty leagues are formats in which at least a portion of your roster carries over from one season to the next. The exact number of players you're allowed to keep varies from league to league, but unlike in single-year leagues, you probably won't be starting from scratch each year.
Perhaps the most important thing to understand about keeper leagues is that they require long-term commitment. Here, owners aren't just focusing on the upcoming season but future campaigns as well. It's best to know the owners and whether they have the right disposition for this type of league.
A sound approach to establishing a keeper league is to expand an existing single-year league. You should already have a good feel for the owners, including their level of both expertise and commitment. Also, don't feel obligated to jump in with both feet and adopt incredibly stringent rules. You can keep it simple at first. You can always expand and alter the parameters as you become more comfortable.
While the decision to convert an existing league can be made at any time, the transition should be handled in a future offseason and well before your draft. That means no one can carry over a roster from the single-year league. It's unfair to ask owners to retain players they chose under different circumstances. All selections and decisions were made based on the belief that they would have their players for only one season.
Determining roster guidelines and draft format
While you might be surprised to see the words "casual" and "keeper" in the same sentence, there are definitely different levels of dedication when it comes to keeper leagues. Those just starting to get involved with the process may want to limit the number of players retained from year to year - say three to five - to keep the draft pool full of talent and keep everyone reasonably competitive from one season to the next. Another possible rule is to limit the number of reserves on each team.
In such formats, owners tend to retain stars or fast-rising players. You may choose to place restrictions on which players can be held. For example, only players selected after a certain round are eligible, or players can be protected for only a set number of seasons. For those playing in auction formats, with a salary cap, you can mandate that a keeper's salary increases by a nominal amount each season.
Serpentine formats are simpler for casual players, in the beginning. If you're uncertain of the reliability of your league members and the staying power of the league, it will be simpler to begin this way. However, if your league already uses an auction, there likely isn't a need to scale it back.
For those who live and breathe fantasy baseball, keeper leagues add a new level of dedication. For instance, you can decide to form a full-retention league (all players owners wish to keep at their required salaries) or one in which each squad can select a very large number of players to keep. Obviously, the more players retained means the fewer available in a draft.
Greater (or no) limits on keepers means you might implement deep reserve rosters. Going further, you may even choose to split them into two categories: a traditional bench and an area for players without major league experience.
With more spots to retain players, owners should focus on not only stars but also young players with high ceilings. The restrictions placed on keepers can mirror those discussed in the casual section, or they can be tweaked in a number of ways. Many leagues strive for realism; hardcore keeper leagues give participants the chance to mirror the role of a real general manager. These elements aren't necessary because the market dictates who is retained based on the league rules, but it adds more of a dynasty concept.
Auctions appeal to serious owners. If you're expanding an existing league to a keeper format and don't already employ one, consider advancing to an auction. Incorporating two large changes takes serious planning, so all owners should just be aware of the commitment.
You can retain whatever system your league uses for free agency, but you may want to alter it if you believe it will add to your keeper league experience. A first-come, first-served system for free agency is fine if you're just beginning. You can also hold weekly waivers, with waiver priority becoming the sole factor in who gets what players.
If you choose a more casual free-agent system, keep in mind that you must determine how to assign a salary to unowned players. This is in case owners retain picked up players into the offseason and must determine their keepers. Your league has two basic options: (1) Assign a default salary to each free agent (say $5), or (2) allow a team's bid for the free agent to become his salary.
FAAB (Free Agent Acquisition Budget, or something similar) systems, which usually hold waivers once per week, allow owners to submit bids for free agents. This is usually the format of choice if your league holds an auction.
Remember to consider the merits of your trade deadline. You may give some thought to pushing it back. In single-year and casual keeper leagues, an early trade deadline may do more to prevent collusion. In serious keeper leagues, this date can be a little later than it is in single-year leagues because moves should be done with long-term goals in mind. However, late-season trades can create tension, so don't open the floodgates.
You may encounter significantly more grumbling about the overall balance of a trade in a keeper league. Teams may deal established stars for relative unknowns with varying degrees of upside. Just remember that trade value is highly subjective in keeper leagues. Commissioners should exercise veto power extremely judiciously; voting owners should keep the same in mind.
Know your software
Make sure whichever site that hosts your league has the necessary resources for it to work properly. For simple keeper leagues, you should find quality options.
If you're looking to implement a lot of unique rules, you'll want to be sure the software can handle so much customization. If you move your league, remember that hosts vary greatly in terms of quality, so make sure you aren't sacrificing other factors such as affordability, ease of use and customer service. Your league may wish to institute many changes, but in some cases, slightly altering your plans by conforming to what your choice host offers is a worthy sacrifice in the name of an enjoyable keeper or dynasty league.