This question comes up from time to time, and while we always take care to answer it, it would be easiest to have a quick reference. So, here you go.
Forget all the symbolism in the former "Leone For Third" site name - that was a different issue entirely. All that matters here is that Justin Leone is a better baseball player than Greg Dobbs, and that the Mariner organization still doesn't see it.
To Dobbs' credit, he's put himself in a good position - he's left-handed, hits for contact, and flashes a beautiful textbook swing, all three of these being attributes that the Mariners appreciate. In addition, Seattle originally drafted Dobbs in 1996, but he never signed (nor did he sign with Houston in 1999), so when they saw him available as an undrafted free agent in 2001, they jumped on the opportunity to prove that they knew something when they first tried to bring him in five years earlier.
So you can imagine how happy they were to see Dobbs tear through A-ball in his first year of professional baseball. He kept hitting for a decent-to-good average and solid contact, and before too long, the organization felt that he could be the third baseman of the future. He got the label in 2003, and promptly missed the season with an injury (allowing Leone to burst onto the scene), but his reputation as a talented ballplayer has remained to this day.
Leone was a 13th round selection out of college in 1999, hitting for power and drawing some walks in his first professional season, but striking out too often and flashing an underwhelming batting average. He improved the next season, but a rough 2001 campaign all but erased him from the organization's radar screen. Leone remained in high-A in 2002, doing what he'd always done and getting little attention.
Both he and Dobbs were slated to begin 2003 in San Antonio, with Dobbs starting at third and Leone becoming the backup/super-utility player. However, Dobbs tore his left Achilles in the second game of the season, and Leone took over as the starter. He took advantage of the lucky break, posting incredible numbers across the board and becoming both the Texas League and Mariner Minor League Player of the Year. With Jeff Cirillo and Willie Bloomquist busy slap-fighting for the starting 3B position in the big leagues, it looked like Leone might have a future with the organization after all.
...except, no, that really wasn't true, because Dobbs moved back ahead of Leone on the organization's prospect list as soon as he was healthy. Leone got promoted first during the lost 2004 season, but that's because he came straight from Tacoma, while Dobbs was busy getting familiar with AAA after beginning the year with San Antonio. Leone did exactly what you'd expect of him - hit for power and draw a few walks while striking out a ton - before Matt Kinney broke his hand with a pitch, and Dobbs would later stink up the joint following a September promotion.
And yet, the organization continued to favor the lefty, and he'd go on to break camp with the big league club in spring 2005, while Leone was sent to the minors after a few weeks. The reason? Dobbs has a "picture-perfect swing", straight out of "beauty school" (seriously, not my words). The team also said that this was a reward for Dobbs having hit at every level, and that they expected him to provide some power off the bench.
This is where we begin to see some problems. First of all, Dobbs hasn't hit at every level - he was awful in AAA (.271/.286/.416), and he's been even worse in the Majors (.224/.241/.303). He doesn't have great power, as 31% of his career hits have gone for extra bases, and he sports a .158 cumulative isolated power figure. To make things worse, he has a lousy batting eye, drawing an unintentional walk once per 17 plate appearances (and once per 84 PA's in AAA/Majors) while striking out twice as often. He may have a great swing in batting practice, but you better believe that it looks pretty bad against good pitchers. Simply put, it's impossible to succeed if you can't tell the difference between a ball and a strike, and Dobbs has had more and more difficultly doing that as he's climbed up the organizational ladder.
And Leone? All he's done is smack 49% of his hits for extra bases and post a career .239 isolated slugging total. He walks more than twice as often as Dobbs (once per 7.5 PA's) and has a better BB/K ratio. And that whole thing about hitting for average and contact? There's virtually no difference between Dobbs and Leone's BA's in AAA/Majors, and although it's a small sample, Dobbs has struck out just as often as Leone with the Mariners.
It doesn't end there, either - Leone has better speed (7.87 to 5.31 in Speed Score), plays better defense (Leone was drafted as a shortstop and has terrific range, while Dobbs is pretty limited), and is more versatile (he has experience in the outfield and the middle infield, while Dobbs is pretty much limited to the corners). When you add it all up, and you realize that Leone is 28 years old and in the middle of his peak, you really begin to wonder why he's stuck behind Dobbs on the depth chart.
It really comes down to a fundamental flaw in the organization - while Dobbs looks like a ballplayer, Leone is a ballplayer, outperforming his pseudo-rival at everything except being left-handed. While Dobbs could eventually peak as Shea Hillenbrand, Justin Leone is ready to be Seattle's own Russ Branyan right now, only with a better glove. He has nothing left to gain in the minors, and appears to be better prepared than Dobbs to contribute to the Major League bench.
But Dobbs' swing? Gorgeous. You can't teach that.