There is no shame in admitting failure.

Well, at least not in a season like this one.

Let's face facts: Three of the top eight players picked on average in ESPN drafts this preseason have missed more than a month's action; the top eight in total have missed 174 team games (that's 22 per player). Five of the top 10 starting pitchers have spent time on the disabled list, and a sixth (Tim Lincecum) has out-and-out stunk.

And, incredibly, a whopping 42 members of the preseason top 100 place more than 100 spots lower on our Player Rater today than was their ADP ranking. Healthy players Lincecum, Ricky Romero, Rickie Weeks, Mike Napoli and Jon Lester, all part of that group, rank outside the Player Rater top 300.

Evan Longoria's status for the second half of 2012 is up in the air because of injury, but he still has plenty of value in future seasons. Andrew Weber/US Pressiwire

It seems that smarts alone won't guarantee you anything in 2012. You need to have luck -- particularly in the health department -- on your side.

Let's say, for a moment, that you have not had a terribly "lucky" season. Perhaps you're the unfortunate owner of Jacoby Ellsbury, Evan Longoria, Lincecum, Dan Uggla, Napoli, Lester, Mariano Rivera, Michael Morse, Jayson Werth and Brett Gardner -- and yes, going by ADP there was an extremely realistic chance that some team wound up with those as its first 10 picks. A team in that position, languishing in eighth or ninth place with little hope of recovery, might understandably be ready to turn the page to 2013.

It is not always the wrong decision to do so. For the most part, fantasy owners are somewhat too quick to throw in the towel; but the ones who clearly understand their team's current situations and are clever enough to craft a long-term strategy are smart to now shift their focus.

Remember, we're now 29 days from the trade deadline in ESPN standard leagues, and as few as 19 or as many as 50 days away in other formats, depending upon your league's custom settings. (Ask your commissioner right now if you don't know.) There is no better time to start preparing for 2013, in a keeper league, than today.

The rankings formula

I've said this before and will reiterate: It is impossible to craft a set of keeper rankings that will be of equal help to every owner, because few keeper leagues are identical. Consider the variables: the player pricing method (draft or auction, and do you keep players in the round they are picked or the auction price you paid, or is there inflation?); number of keepers (can you keep one, three, 10 or possibly your entire roster?); and length of keeper contract (can you keep a player for only two or three seasons, or can you keep a player forever without penalty?).

Whether you're in contender or rebuilder mode also has an impact on your personal keeper rankings, as does your philosophy regarding those two modes. For example, I've known many a contender who, in spite of his or her best prospects at a championship, still will not completely let go of the "rebuilder" in him/her, even at the possible expense of said title.

You'll need to do some of your own calculations to tweak these keeper rankings for your needs. There is absolutely no chance, for instance, that I would trade a $9 Matt Moore for a $22 Adam Wainwright if I was in rebuilding mode, despite my ranking Moore 15 spots higher. As a contender, however, I might well consider it though I'd probably push for a little more thrown back.

This is the player valuation formula I used:

• 2012 second-half performance: 10 percent.

• 2013 performance: 22.5 percent.

• 2014 performance: 22.5 percent.

• 2015 performance: 22.5 percent.

• 2016 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 2012 -- scaling that percentage to remaining games -- is equal in weight to 2016, remember that we already provide rankings for fantasy owners focusing solely on this year; they were published Tuesday and can be found right here. If you're a keeper-league owner still in the hunt in 2012 -- that's always what I advise, if you have even the slightest chance of winning -- consider this list should more of a "price guide" as to what kind of rental pieces you might acquire for your up-and-coming prospect.

Tristan's Top 250 keeper rankings

Note: Position eligibility is determined based upon a minimum of 20 games or the position the player appeared at most often in 2011, or 10 games played at a position in 2012. Players' anticipated future positions are considered in the ranking. Players' listed ages are as of July 13, 2012, the first day of the second half of the season. Players' rankings in past keeper lists are also provided: "2012 Pre" are rankings from the 2012 Draft Kit, "2011 Mid" are from July 2011, "2011 Pre" are from the 2011 Draft Kit, "2010 Mid" are from August 2010 and "2010 Pre" are from the 2010 Draft Kit.