Over the last couple of years, I’ve expressed an amount of skepticism relating to Jesus Montero’s status as an elite prospect. Essentially, my argument has been that since Montero is likely to be the kind of player who produces all of his value at the plate, he’s going to have to develop into a monster hitter to justify the expectations placed upon him. For bat-only players, the offensive bar to become a superstar is extremely high, so Montero would have to become one of the very best hitters in baseball to be a truly elite player.

The counterpoint has usually been that Montero is going to become one of those hitters, with scouts comparing his offensive profile to Mike Piazza and Miguel Cabrera, among others. He’s extremely strong, he’s got pretty good plate coverage, and he’s held his own in the minors while being pushed aggressively up through the minor leagues. Several of the game’s best hitters had very similar development paths, and it’s clear that Montero could develop into that kind of offensive force. Given what the Mariners paid to get him, they’re clearly hoping for that outcome.

Still, Cabrera and Piazza are Montero’s ceiling – the best possible outcome if he continues to develop, stays healthy, and maximizes his physical abilities – but projecting a player solely based on upside will often lead you astray. In evaluating Montero as an offensive prospect, we need to not only know what his ceiling would be, but the range of potential outcomes and the likelihood of each one coming to pass. To find a more complete picture of what a Montero-style hitting prospect usually turns into, we turn to history and the lessons of players who were lauded in similar ways as Montero is now.

While Montero’s minor league performances have been good and sometimes great, it’s his scouting reports that have established him as a monster prospect. So, instead of pulling in data on players who hit similarly in the minors, we’re better off developing a list of historical comparisons based on guys that were seen as future stars through the eyes of scouts that covered them. For that, we turn to Baseball America’s All-Time Top 100 list, which serves as a valuable reference to remind us of how prospects have panned out throughout history.

The lists go back to 1990, giving us essentially 20 years of prospect evaluations, a more than adequate timeframe to find a solid sample of players who were viewed in their time as Montero is now. From the BA rankings, I compiled a list of 22 guys who fit a similar mold as Montero – top 10 prospect, reached Triple-A around age 20 or 21, and showed significant power during their time in the minors.

There were some judgment calls to be made on which guys made the list of comparable players and which didn’t. Cliff Floyd, for instance, was rated the best prospect in baseball in 1994, but that was based more on his athleticism and skills as a five-tool guy than as an elite hitting prospect – he showed minimal power at high levels during the early part of his career. Since I was trying to limit the list to guys whose value was primarily based on what they could do offensively, Floyd was left off the list, as were other highly rated youngsters (for example, Joel Guzman, Jeffrey Hammonds, Corey Patterson, Ruben Rivera, Ruben Mateo, and Colby Rasmus) who didn’t really fit the elite-hitter model of a top prospect, or who just had a very different skillset than Montero (Jeremy Hermida, Casey Kotchman, and Nick Johnson, for instance). I wanted the list to represent players rated as elite projectable hitting prospects through the years, as best as I could, and including those types of players on a list of comps for Montero doesn’t really seem to help us understand what he might become as a hitter.

For this reason, I also excluded guys who were several years older and more developed than Montero (J.D. Drew, Alex Gordon, Pat Burrell, and Mark Teixeira) when they were rated as elite offensive prospects.

To the 22 guys who fit the profile, I added Piazza and Miguel Cabrera, since they are so often referenced in regards to Montero’s future. That gives us 24 elite young hitting prospects with fairly similar profiles to Montero. If you disagree with some of my selections, that’s fine, as there’s obviously subjectivity in the decision making process. You can use the custom player list and the link to BA’s historical rankings to add or subtract any players you wish, and then easily see what kind of difference it makes in the final results.

I think most reasonable list of comps will return similar conclusions, but for reference, here’s my list, along with their career hitting stats:

The success rate here is obviously pretty good. Of these 24 players, I think you could reasonably argue that nine of them turned into elite hitters, all posting a career wRC+ of 128 or higher, and regularly beating that during their primes. That’s nearly 40 percent of the list, and these are the types of hitters that scouts clearly have in mind when they talk about what Montero could be.

However, we can’t ignore the other 15 guys who were also deemed to be top-notch prospects and haven’t turned into that kind of impact offensive bat. I know its tempting to look back at guys like Andy Marte, Karim Garcia, and Delmon Young as just examples of players who were overrated prospects, but they all had track records to support the strong scouting reports as they rose through the minors. They were young for their leagues, they showed the ability to drive the baseball, and expectations were that they would develop into All-Star caliber players. Instead, they were all replacement level scrubs, though Young still has some time left to try and show that he could just be a late bloomer.

Beyond those three busts, however, there’s 15 guys who represent perhaps a more realistic median projection for Montero – Upton and Bruce’s best days are expected to be ahead of them, so they’ll push the overall levels of this group up a bit (and Upton may very well be headed for tier one himself), so you’re probably best off viewing Montero’s median expected production towards the higher side of this second tier. Ranging from Paul Konerko (121 wRC+) and Shawn Green (119 wRC+) on the high side to Hank Blalock (100 wRC+) and Vernon Wells (105 wRC+) on the low side, these guys all turned into good-but-not-great hitters, and it mostly had to do with their ability to control the strike zone.

For the top nine guys on the list, the median walk rate was 11.1% and the median strikeout rate was 17.8%. For the 15 guys in the middle, the walk rate falls to just 9.8%, though the strikeout rate is almost exactly the same, coming in at 17.7%. A significant part of the difference beween the elite hitters and the good hitters isn’t the ability to put the bat on the ball, but in how well they’re able to adapt to pitchers throwing them pitches out of the zone. Cabrera, for instance, wasn’t the most patient hitter in the minors either, drawing just 24 unintentional walks in 303 plate appearances during his last stop in the minors, but as pitchers started giving him fewer pitches to hit, he’s developed into a guy who is willing to take first base if it’s offered.

Adrian Beltre and Aramis Ramirez have never made that adjustment, and it has limited their overall offensive output throughout their careers. Even Konerko, the best hitter of this second tier group, didn’t really begin to accept the base on balls until age 28 – not coincidentally, the second half of his career has been a lot better than the first half was. In fact, as a similarly-sized, right-handed converted catcher, Konerko might be the single best comparison for Montero’s expected career output of any player in the game today.

The upside for Montero to be a Cabrera, Piazza, or Fielder is real. However, history suggests that it is not the only path, or even the most likely one, for Montero to take. There have been a lot of prospects who received similar accolades for their offensive potential who have handled the upper levels of the minors at young ages as well. We’ve identified two dozen of them here, and the median slash line from this group was .281/.349/.491, good for a 117 wRC+.

That’s a nice hitter, but it’s not the kind of bat you can build a franchise around. For Montero to reach the upper tier, he’s simply going to have to show a bit more selectivity at the plate, and adapt to facing a good number of pitches out of the zone. If he makes that leap and improves his command of the strike zone, he could be a monster. But we need to recognize that it’s still an if, not a when. Some guys never figure that out, and if Montero doesn’t either, he’ll settle in as a good hitter rather than a great one.