Making the decision whether to buy or sell isn’t just about your team’s record in the second half of July. You have to take into account the overall direction of the organization, the level of competition, your team’s ability to add what it needs, and whether doing so will make the difference both in the current season and what it will mean for the ones that follow.

There’s perhaps no team with a more complicated set of factors to consider than the Texas Rangers, who are on pace to win 90 games, have a positive run differential, and who could clearly use the top player on the market, Roy Halladay. With one of the very best farm systems in the game, the Rangers can put together a package that would be the envy of all suitors, not just for Halladay but for any player they pursue. However, by doing so, they might be chipping away at what sets up as a dynasty in the AL West for years to come, and even adding Halladay wouldn’t assure them of anything given the standard for contention in their league.

The Rangers are a legitimate 51-41. They’ve outscored their opponents by 36 runs, and while their third-order record is a bit less impressive-48-44, the eighth-“best” mark in the AL-it’s close enough to their actual record. They’ve caught a break in that their pitching and defense have allowed fewer runs than you would expect, and they’ve outplayed their Pythagorean record slightly thanks in part to a 14-9 record in one-run games. As I wrote about earlier this season, their offense has shown a complete lack of understanding of the strike zone, leading the league in strikeouts while drawing just 273 walks, 12th in the AL. They’re living off of their performance on contact, which is down to a .332 batting average and .589 SLG from the .360/.641 marks that drove their 23-14 start to the season, and right around their league-leading marks in 2008. The current performance is their level of ability, which makes them a league-average offense or so, not the offensive juggernaut their power makes it seem. They simply don’t get enough guys on base to have a good offense.

Check the pitching staff and you find the opposite problem, as the Rangers are dead-last in the league in pitcher strikeouts. That they’ve been able to keep their opponents off the scoreboard is a credit to the best defense seen in the Metroplex since the 1990s Cowboys. Adding Elvis Andrus to the mix has been a boon, and while his performance is slipping as we get deeper into the season, he has been a big reason why the Rangers’ Defensive Efficiency and PADE are both fourth in the game. (Chris Davis also showed considerable dexterity at first base while he was in the majors.) This was a different run-prevention team this year, and that trait should carry forward into future seasons; when the high-strikeout pitchers arrive, this will be a very difficult team to score upon.

For this year, though, I’m not sure the Rangers can continue to keep their opponents down. The bullpen’s peripherals are fine, with the primary problem being Frank Francisco‘s incessant health problems. The rotation, however, features just a single starter with a 2:1 K/BB, that being Derek Holland, who has allowed nine homers in 43 innings in eight starts. Only Holland has an above-average strikeout rate as well. The rotation’s lack of top arms is the biggest reason to favor the team adding a Halladay, who would not only push them towards the Angels this season but give them a leg up in 2010. I’ve said in the past that adding Halladay would make the Rangers the AL West favorites, but I’m less convinced of that with each passing day, as the Angels play better and better baseball. Since John Lackey made his first real start on May 18, giving the team its more-or-less intact rotation, the Angels are 36-20. What the Rangers want to avoid is making a big deal and still not getting to the middle of October.

The combination of being slightly over their heads, having underlying metrics that indicate some slippage is ahead, chasing a team that, when healthy, has been very good, and having little chance to take the league’s wild card… the mix is bad for the Rangers. To invest what it would take to bring Halladay in, which would be some combination of Holland or Neftali Feliz to start, then another two prospects from their top dozen at least, is more than they need to bet on a season that isn’t critical to their future. I’m not sure it makes sense for them to make a second-tier move, either, although the idea of acquiring Matt Holliday is interesting for a team that has BA and OBP issues, and has built around defense this year.

Context is everything. In a vacuum, the Rangers are five games better than the Astros, who I positioned yesterday as a buyer. Given what the Rangers would have to do to make the playoffs, though, and where they are in the success cycle, for them to make an over-the-top trade doesn’t make sense this year. It probably wouldn’t get them there, and it would take a big chunk out of their future. I see an argument for trading a number of their pitching prospects to add one ace starter-it’s one way to “develop pitching”-but that kind of deal should be made in the offseason, and for a pitcher who can be retained for a long time.

Should the Rangers then be sellers? There’s a case for it, perhaps shopping Kevin Millwood, Hank Blalock, C.J. Wilson, and others who would have value in the market and who have no role on the team going forward. Millwood, having his best season in years, would be one of the top pitchers on the market, and a number of teams could use a bat on the corners. However, and this is not a position I usually advocate, the Rangers don’t have to make that kind of trade. The prospects they could get for players such as Millwood and Blalock would be a drop in the bucket in their system, and the bad PR involved in trading away veterans during a successful season could be damaging. The Rangers are that rare team that should be neither a buyer nor a seller, simply riding it out with the roster they have, treating this as a bridge season between their building years and their extended run of success.

Not far behind the Rangers are the surprising Mariners, 49-44 and 5½ games behind the Angels. Coming off of last year’s terribly disappointing campaign, and riding the wave of a strong rotation and a couple of big hitting performances, there’s some idea that the Mariners should capitalize by trying to add a couple of pieces for a run. This would be a mistake, and Jack Zduriencik knows this. The proper move for the Mariners is to convert Jarrod Washburn, Erik Bedard, Russell Branyan, and anything else not nailed down to reinforce their mediocre farm system. The Mariners aren’t good enough to win this year, and probably not next year, and the prospects they could get for their veterans over the next couple of weeks-not top-25 guys, to be sure-would have an impact for them. It’s time to sell.

We’ll spend tomorrow on one team that has every reason to think it can hang with the big boys… and has no business trying.