Spring training is both a blessing and a curse for baseball fans. We love it because it’s a sign that winter is at an end, and we can finally stop all of the guesswork about who signs where and for how much, and just concentrate on the games. Truth to tell, we also despise spring training, though-we just want the season to begin, and we want games and numbers that matter. Only a few weeks in, it may still be spring training, but numbers that matter are just what we’re going to be looking for today. As fans who have dealt with speculation and uncertainty all winter long, we want to read about our favorite players being in the best shape of their lives, or hear that they’re seeing the ball better then they ever have, because those are the stories that help us get through the preseason.

The reality of the situation, however, is that these occurrences rarely portend improved play. Just because we want our favorite scrub to be capable of continuing to slug .500 for more than these four weeks does not mean that it will happen, but on the other hand, it also doesn’t mean that all of the numbers accumulated in the preseason are worthless.

John Dewan, formerly of STATS, Inc. and currently the owner of Baseball Info Solutions, stated that if a player posted a pre-season slugging percentage 200 points above their career rate, you could expect the player to improve during that season. There have been studies to show that, yes, Dewan is on to something here, but the return rate on these instances is low. There are a few reasons why it’s difficult to accept this as a general truth. First of all, we’re working with a very small number of such players; even a full season’s worth of data often isn’t enough for a player’s numbers to even out, so a handful of at-bats just won’t do for research purposes. Secondly, those at-bats have even less meaning when you consider that many of them have come against career minor leaguers filling in holes on the B-squad, or against pitchers working out the kinks in their arsenal, trying out new pitches, and attempting to do things that they might not do in a regular-season game.

Even with those caveats, there are times when Dewan’s words ring true, and this has fantasy baseball implications, especially for leagues drafting later in the spring. Knowing what to look for can help you fill out your roster with sleepers in the later rounds. As an example, Nate McLouth had a solid enough season in 2007 (.258/.351/.459), but he then proceeded to hit .359 and slug .718 during spring training the following year. He continued to make better contact during the regular season both in and out of the strike zone, which resulted in fewer strikeouts, a higher average, and a bump in his power production.

Jody Gerut is another player whose pre-season statistics can tell you a lot in hindsight. Gerut is just the kind of player you normally want to ignore in spring training, as he was out of the game and the majors for a few seasons, and then suddenly appeared in San Diego’s camp, the kind of thing you’ll see often if you peruse box scores at this time of year. He hit .303 and slugged .697, which was enough to convince the Padres to stick him in Portland and see what would happen. He tore up Triple-A, earned an invitation to the majors, had the best season of his career, and he’s now slated to get the bulk of playing time in center field for the Padres this year.

There were others of course: Skip Schumaker played well during a short major league stint in 2007, and after slugging .542 in spring training, the Cards gave him a shot at an everyday job; he responded by hitting .302/.359/.406 while playing average defense, helping the Cardinals out with their injury issues in the outfield. Chris Iannetta, who many felt had not been given a shot at the starting catcher’s job in Colorado, slugged .565 in spring training and went on to post an Isolated Power (ISO) of .240, over 100 points better than his career rate.

Of course, for every success story, you have a handful of failures. Out of the roughly 950 batters who accumulated at least one hit during spring training in 2008, nearly 400 of them slugged .500 or better. Just 52 hitters reached that mark in ’08 for the full season (minimum 400 plate appearances), and the major league-average slugging rate was .416. The list of hitters who did not improve is full of players of all types, though for the purposes of this exercise, just know that established veterans who beat up on pitchers during spring training are not the best bet to follow through into the season. Bobby Abreu slugged .733 during spring training, and then ended up with a season very similar to his past two campaigns-productive, but certainly not stellar. Torii Hunter may have made some Angels fans happy when he tore up the opposition in last spring with a .944 slugging percentage, but he ended up with a season that wasn’t close to being worth the lucrative contract he had signed that winter. Jason Varitek slugged .720 during spring training, a number that would prove to be higher than his combined on-base plus slugging percentage for the year.

How can fans, analysts, and fantasy owners tell the difference between the players who are actually improving, and those just racking up meaningless numbers? That’s a difficult question, and one with no clear answer. Scouts have the advantage in situations such as these, and they can see who is changing their approach: who is closing up the holes in their swing, hitting that inside fastball that always gave them trouble, or learning to go the other way with outside pitches. Who is laying off of pitches in the dirt or up high, showing better plate discipline and strike-zone judgment, setting themselves up for better numbers and maybe an extra burst of legitimate power?

Unless you have a keen eye for that sort of thing, you are going to need to rely on box scores for your information to see who is hitting against real pitching, and who is just pumping up their own numbers against a Triple-A lifer who may as close to the majors as he’ll ever get. This time of year, how they reach (or fail to reach) these numbers is more important than the numbers themselves; keeping abreast of that information and its context can help as you follow your favorite team or plan out your fantasy lineup until the time when the real games begin.