The majority of fantasy baseball players on the planet only need to worry about a pool of 300-400 major leaguers. The world is filled with normal people who just want to fill out a starting lineup with household names, make a few savvy pickups, and beat the competition to a promising youngster or two as the season progresses.

This will not be a series for such people.

Instead, we’re targeting brave souls of unwavering dedication and questionable sanity who play in AL- and NL-only formats or the deepest of mixed dynasty leagues. You don’t want to know about established major leaguers, because they’re already owned. You don’t want to know about top 100 prospects, because they were claimed long ago. You need to go deeper.

But, much as you shouldn’t grocery shop when you’re hungry, you shouldn’t scour the waiver wires or minor-league box scores when you’re desperate or don’t know what you’re looking for. And so, with considerable assistance from the MiLB team here at BP, we bring you the Fantasy Fool’s Gold series: a position-by-position breakdown of minor leaguers who might tempt you, but who may not provide the fantasy oomph you so desire.

We begin with five catcher and first base prospects who, unlike so many Transformers, might be less than meets the eye.

Christian Bethancourt, C, Braves
Long considered one of the best defensive catching prospects in the game, Bethancourt has improved offensively this season. He’s hitting .283/.311/.446 in 371 plate appearances as a 21-year-old in Double-A in 2013. That compares quite well to the .243/.275/.291 line he put up in 288 PA last year at the same level. Bethancourt is hitting for more power than he has at any point since Rookie ball and his triple-slash line is quite attractive for a catcher, so why should fantasy owners still hesitate to vie for his services?

Bethancourt’s approach at the plate is quite aggressive, and he has a hole on the outer half that pitchers can exploit. He’s able to survive off of excellent hand-eye coordination, but his approach leads to too much weak contact. Bethancourt is also allergic to walks—his BB% of 4.0 this year is actually the highest of his career in any meaningful sample—meaning that he’s not going to be on base very often unless he makes harder contact or he gets lucky with BABIP.

The stats suggest that Bethancourt has taken a step forward this season, and his defense will likely keep him in the majors for a quite a while. That being said, he possesses neither the offensive upside nor a high enough probability to make him particularly appealing to fantasy owners in mixed leagues. This is a prime example of a prospect with much more value in real life than for our purposes.

Gregory Bird, 1B, Yankees
While many of the other players on this list don’t warrant fantasy attention at all, that is not the case with Bird. Initially drafted as a catcher, Bird was moved to first base late last year, which doesn’t help his prospective fantasy value. Despite the downgrade in positional eligibility, Bird has burst onto the scene as a prospect to watch this season.

The first thing that jumps out at you is Bird’s impressive .289/.423/.517 line, but what might be most impressive is that he’s currently walking in 18 percent of his at-bats in a meaningful sample size of 555 PA. Bird is whiffing in 23.2 percent of his PA as well, but if those ratios were sustainable (and they’re probably not), that’s certainly a tradeoff you’d take.

Whether Bird can sustain this type of success is up for debate among those who have seen him play. On the one hand, Bird’s power is labeled as legit and he’s complimented on a short and direct swing. On the other hand, there are doubts surrounding how much contact he’ll make against advanced pitching, and his swing, while powerful, has some holes. It’s important to note that Bird is still just in Single-A, so any fantasy value is purely speculative anyway. But while Bird probably deserves an add in very deep leagues, he’s not someone you should burn a ton of salary on or keep on a roster in shallower keeper leagues. This is still a first-base prospect we’re talking about, and until he demonstrates the ability to hit at a higher level, he should remain unowned in the majority of dynasty leagues.

Jordan Lennerton, 1B, Tigers
Lennerton entered the season to relatively little fanfare, as 27-year-old first basemen with no experience above Double-A are wont to do. He’s put himself on the map, though, by posting a .279/.384/.431 line in Triple-A and making the Futures Game. He’s perhaps most famous around these parts for making said game over the likes of Carlos Correa, much to the chagrin of everyone not in the immediate Lennerton family.

Despite his impressive tripe-slash line, 17 homers, and .285 TAv this season, there’s not much reason for optimism for fantasy owners. Lennerton lacks the type of bat speed and control requisite for consistent success in the majors and his power profile is just average for first base. He’s a gifted fielder at first but is limited to that position defensively. Lennerton has displayed an impressive approach and ability to reach base, having never posted a BB% below 12.4, but unless you’re in a two-first-basemen OBP league, that’s not going to cut it in fantasy.

While this probably goes without saying, there’s not much room for playing time ahead of Lennerton in his current organization, meaning he’ll only get a real crack at some PAs if the Tigers deal him in the offseason. Even if that happens, he projects more as an up-and-down guy than someone who will see consistent playing time. Long story short, Lennerton is a player/lumberjack who’s having a nice season and deserves a cup of coffee this September, but he’s not worth owning even in AL-nly leagues.

Maxwell Muncy, 1B, Athletics
There aren’t a lot of (or maybe any) elite fantasy first-base prospects right now, but 2013 has seen several first basemen in the low-to-mid minors significantly enhance their value. Muncy fits in this category, as the 23-year-old has reached Double-A in his second professional season. As an older player without massive pop, Muncy didn’t get much love before the season began, but he’s forced his way into the conversation in AL-only or (very) deep mixed dynasty leagues.

Muncy’s stats in 428 High-A PA this season were quite impressive. The lefty hit .285/.400/.507 with just a .295 BABIP and walked essentially as often as he struck out, posting marks around 15 percent in each category. Unfortunately, those numbers were artificially bolstered by his home ballpark in Stockton, in which he slugged more than 70 points higher than on the road and at which he hit 15 of his 21 homers. Since his move to Double-A, Muncy has hit just .234/.324/.351 with two homers in 176 PA.

The good news is that Muncy’s ability to hit is not in doubt. Described as a potential “5” tool, the bat is legit and should continue to be legit as Muncy makes his MiLB ascent. The bad news is Muncy doesn’t bring much else to the plate from a fantasy perspective. He does not project to hit for even average power from the position, and he’s not athletic enough to move off of first base. Good defenders and hitters often find themselves in the majors regardless of other deficiencies, but from a fantasy standpoint, Muncy has more weighing against him than in his favor right now. Don’t fall for his Stockton numbers.

Christian Walker, 1B, Orioles
A fourth-round pick out of South Carolina in the 2012 draft, Walker’s ascent through the minors has been a quick one. Just 532 PA into his professional career, Walker already finds himself in Double-A having received a promotion last month. That promotion was well earned, as Walker torched Single-A for 31 games before hitting .288/.343/.479 in 239 PA in High-A. With a paucity of fantasy-relevant first basemen in the upper minors, is Walker someone we should monitor closely?

The consensus seems to be “sort of.” Walker has slowed down a bit through his first 17 games in Double-A, but there’s not much we can learn from that. Similar to Muncy, he’s widely praised for his professional approach and his ability to square up the ball well, but that’s where his offensive strengths end. He doesn’t project to have even average power from first base, and Walker is physically maxed out, meaning he won’t add more pop as he ages (and he’s already 22).

The sense I get from those who have seen Walker is that he’s a decent bet to reach the majors, but only as a second-division regular, and that’s his ceiling. That he’s limited to first base really hurts his fantasy value, as the problem here is less that he can’t hit and more that he can’t hit enough to justify playing time at such a demanding position. Keep your eye on Walker in AL-only and insanely deep leagues, but don’t expect him to rank among the best fantasy first-base prospects.