Miguel Cabrera, Giancarlo Stanton and Billy Hamilton carry widely different keeper values. Getty Images

There is no such thing as a fantasy baseball offseason.

Fantasy football is great and all, but my advice to you is this: Hurry up and get that lineup set so you can get back to your fantasy baseball planning. If you don't, you can be sure that some of your competition is, and they're going to have a significant advantage once spring training begins next February.

Here's one place to start: Listed below are my now-triannual top 250 keeper rankings. I say "now-triannual" since these had previously been biannual -- February and July -- but let's just say I caved under the demand; many have asked for more updates to this list. These rankings serve as a "price guide" of sorts for dynasty or keeper leagues, be they already existing or just starting from scratch today.

The rankings formula

You know the drill: Here's where I remind that it is impossible to craft a set of keeper rankings that will be of equal use to every owner, because few keeper leagues are identical in structure. Consider the variables:

• Player pricing: Do you draft or auction players, and do you keep players in the round they are picked, the auction price you paid, or are prices irrelevant?

• Number of keepers: Can you keep one, five, 10 or perhaps your entire roster, and must teams retain the same number of players?

• Contract length: Is there a limitation on the number of seasons you can keep a player, and is there annual price inflation?

• Farm teams: Does your league include minor leaguers, and do these players automatically carry over, or are they also priced?

• Your contender status: Are you in the hunt, in a rebuilding state or are you somewhere in between? At midseason, the answer to this question is far more critical than it is during the offseason.

It's up to you to do the homework assessing each of these valuation factors, recalculating, if necessary, these keeper rankings for your needs. This is the player valuation formula that I used:

• 2015 performance: 20 percent

• 2016 performance: 20 percent

• 2017 performance: 20 percent

• 2018 performance: 20 percent

• 2019 performance and beyond: 20 percent

The rationale for placing equal weights on 2015 through 2019 and beyond is simple: I regularly provide going-forward rankings for the current season and, next week, I'll provide my preliminary rankings for 2015 alone. In other words, I -- and ESPN's fantasy team as a whole -- will publish plenty of 2015 rankings, projections and profiles to help you in the coming months, but right now, fantasy owners in keeper/dynasty leagues might be required to make critical roster decisions before the offseason arrives. While 2015 might warrant a greater weight in a keeper league drafting fresh this upcoming winter, this page was designed to help those fantasy owners who need to make their keeper decisions now -- those who need to project forward for the long haul.

Consider this list the equivalent of a "price guide" for determining appropriate trade or keeper value for your up-and-coming prospects and youngsters.

Tristan's Keeper Top 250

Note: Position eligibility is projected for 2015 based upon 2014 data through Sept. 16, and is determined based on a minimum of 20 games, or the position at which the player appeared most often in 2014. Players' projected future positions -- 2016 and beyond --- are considered in the ranking.

Tristan H. Cockcroft's Keeper Top 250