Top 250 keeper-league rankings

Let's face a simple reality: You cannot win every league every season. No matter how hard you try, it just won't happen.

This is especially true in a keeper, or "dynasty," league, where long-term roster construction takes on both greater importance and difficulty, and where contender-pretender trades can quickly shift competitive balance in-season. To win your keeper league is to achieve an honor worthy of acknowledgement.

Conversely, to know when you can't win is also a skill deserving of praise.

Perhaps as critical as adding those final pieces to a championship puzzle is recognizing these two season stages: The first is when your keeper-league roster is doomed to be an also-ran in the given season; the second one is when your keeper league's trade market offers the richest prospect haul. These two do not necessarily coincide; that's why recognizing each and deciding when to act is such a critical skill of a keeper-league owner.

Generally speaking, this is about the time of year when those stages arrive. Trading season is heating up, with the deadline in ESPN standard leagues arriving 16 days from now. In your league, perhaps it arrives in 14 days, or 45, or some number in between. (Ask your commissioner or check your league settings immediately if you don't know.) It's up to you to determine the best time for your team to act, and the peak point of the trade market in your league.

Today, let's give you a head start on your planning with one of my most requested columns: It's time for a midseason update to my top 250 keeper-league rankings.

The rankings formula

As always, I remind that it is impossible to craft a set of keeper rankings that will be of equal utility 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 1, 5, 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?

It's up to you to do the homework assessing each of these valuation factors, recalculating, if necessary, these keeper rankings for your needs. For example, there's no way I'd trade an $8 Domonic Brown for a $28 Jay Bruce if I wasn't in contender mode, despite the fact that Bruce ranks 21 spots higher. As a contender, though, I might consider it … though I'd probably push for an additional perk, like a throw-in or some auction dollars, considering their close rank but disparity in price.

This is the player valuation formula I used:

• 2013 second-half performance: 10 percent.
• 2014 performance: 22.5 percent.
• 2015 performance: 22.5 percent.
• 2016 performance: 22.5 percent.
• 2017 performance and beyond: 22.5 percent.

The rationale for these numbers is simple: Equal weighting for each of the upcoming four seasons as well as the remainder of this one. As for why 2013 -- scaling that percentage to remaining games -- is roughly equal in weight to 2017, bear in mind that we already provided updated rankings for fantasy owners focusing solely on this year; they were published Wednesday and can be found right here. If you're a keeper-league owner still in the hunt in 2013 -- that's always my primary recommended strategy, if you have even the slightest chance of winning -- consider this list more of a "price guide" for determining appropriate trade value for your up-and-coming prospects and youngsters.

Tristan's top 250 keeper rankings

Note: Position eligibility is determined based on a minimum of 20 games or the position the player appeared at most often in 2012, or 10 games played at a position in 2013. Players' projected future positions are considered in the ranking. Players' listed ages are as of July 16, 2013.

Players' 2013 preseason ("2013 Pre") and peak rankings in past keeper lists ("Prev. Peak") are also provided: These lists have been published semiannually since 2010, with "preseason" and "midseason" designated to differentiate the different times of the years in question. For example, Jason Kipnis is listed with a peak of 44 at "2012 Midseason," meaning that his best all-time rank was 44th, in the July 2012 list. A "--" means that the player has never before cracked my keeper rankings.