The 10 worst position players in baseball (so far)

Juan Pierre is not having a good season. The 35-year-old is hitting .237/.283/.292. He can still fly around the bases, but that's because he literally has wings (which is why he has trouble throwing a baseball 20 feet). If you buy into the wins above replacement over at Baseball-Reference.com, all sorts of familiar names are having worse seasons, though. Matt Holliday, Matt Wieters, Pablo Sandoval, and Miguel Montero are all struggling, just to name a few, and there are some bad seasons floating around out there.

Then there are the worst seasons. Now, is Rickie Weeks's -0.8 season worse than Dan Uggla's -0.1 season? No. Maybe. Dunno. WAR isn't supposed to be that fine. But if you want a list of the 10 worst seasons in the majors thus far, you can make one. And I did.

Here are the 10 worst qualifying seasons by WAR according to Baseball-Reference.com, along with a made-up number that indicates if we should have seen this coming:

10. Mike Moustakas, -0.4
Should-have-seen-this-coming index (on traditional 20-to-80 scouting scale): 35
It's probably always a good idea to be bearish on hitters who accumulate a ton of value with their defense. Moustakas was one of the better third basemen last year, as he was worth three wins despite a .296 on-base percentage. Half that value came from his power (20 dingers) and half from his defense. The defensive boost has disappeared this year, though, because single-season defensive metrics are fickle things.

I think we could have foreseen the fickle defensive numbers and subpar OBP, but the power disappearing is pretty surprising. Even weirder is that his strikeout rate has plummeted, down to 13.6 percent after being at 20.2 last year ... yet he's still having a miserable season despite the improved contact. This is probably a good place to point out that his career minor-league OBP is .337, so maybe he's always been more Matt Dominguez than Ryan Zimmerman anyway.

9. Michael Young, -0.5
SHSTC Index: 80
Ruben Amaro, man. He is a stubborn fellow. Young was a 36-year-old DH coming off his worst season and Amaro thought he would be a fit for the Phillies at third base. That is some serious belief that your powers of evaluation are stronger than the rest of the world's. You have to really think you're seeing through the matrix to make that move.

Young isn't hitting that poorly -- .285/.340/.403 -- so that's a pretty good bounce-back season, but he can't field. He is incapable of fielding. He makes mental mistakes, he makes physical mistakes and he has the range of a sunflower. His defense is bad enough to negate all of his offensive contributions.

Side note: Check out these crazy micro-splits:

Whoa. Dig that BB/K ratio in June. But it worked, kinda. Still doesn't mean he can field.

8. Placido Polanco, -0.5
SHSTC Index: 80
Placido Polanco's last halfway-decent season as a hitter was in 2011. His last good season was in 2008. He had a .257/.302/.327 season with the Phillies last year while suffering from the following aches and pains: back (DL twice, eventually ending his season), wrist and ankle. He's 37 now. He's lost a step or three in the field.

Other than that, I'm sure the Marlins had some great reasons to think he would work out. Hey, at least the Phillies didn't keep him around. Then they'd have the #8 guy instead of the #9 guy on the list ... and that would be awful.

7. Rickie Weeks, -0.8
SHSTC Index: 45
We're in year two of bad Rickie Weeks, which doesn't make a lot of sense. He's only 30 and there's no real good reason for him to lose a few hits out of every 100 at-bats, which is pretty much the problem. He's a .220 hitter instead of a .270 hitter now, and that comes with corresponding drops in OBP and SLG.

WAR has never liked his fielding, either. So here we are. It's worth pointing out, though, that Weeks was much worse in the first half last year, and he hit .261/.343/.457 in the second half -- pretty much his career numbers. So maybe that hitter is still in there. Somewhere.

6. Alejandro De Aza, -0.8
SHSTC Index: 30
Warning: Defensive samples ahead. According to the numbers, De Aza was an average defender in 2011 and 2012. Also according to the numbers, De Aza is carrying Adam Dunn around the outfield in a Yoda backpack this year. I'm skeptical. His offense is down a bit, but he's got a 96 OPS+ -- not too far off his career mark of 100. His defensive numbers are abysmal enough, though, to make him the sixth-worst position player in baseball.

4. B.J. Upton, -0.8
SHSTC Index: 25
If you thought Upton was a good offensive player, you were pretty confident that Tropicana Field was an extreme pitcher's park. If you thought Upton was okay, you were probably like the rest of us. But no one can ever predict a 28-year-old getting completely screwed into the ground like this. Strikeouts up, extra-base hits down, more grounders, more infield pop-ups and just 43 hits in 283 plate appearances. Seven of those were infield hits.

The worst part about the ranking: it has nothing to do with defense because Upton is rated higher than he has been in other seasons. Actually, the worst part about the ranking is everything. Everyone thought it was a good thing that he joined his brother, but maybe his brother just whales on him around the clock like mine did.

Wait, but B.J. is the older one. None of this makes sense.

5. Adeiny Hechavarria, -1.1
SHSTC Index: 65
Hechavarria was a career .273/.315/.382 hitter in the minors and that includes 450 at-bats in Las Vegas, which is like Coors Field without the humidor. He was never especially young for his level, either, so he wasn't expected to hit. He was supposed to be a pretty good defender and that part's been true, at least.

He was never supposed to be a jaw-dropping, golden god in the field, though. Combine that with the lackluster career in the minors and a season like this was always possible when he was made a full-timer.

3. Paul Konerko, -1.0
SHSTC Index: 50
He is 37, after all. But another consideration for the SHSTC is that WAR hasn't gotten along with Konerko for years. Something about a fence line and city permits, maybe? Seems complicated. But they hate each other. Konerko has 429 career homers and a career .358 OBP.

His career WAR is 29 -- Mike Trout is halfway there, by the way -- which puts Konerko in the vicinity of Melvin Mora and Alex Rios. Good players, but not exactly perennial All-Stars. Other than a couple of outliers, the typical season for Konerko is about two wins. Add that to his advancing age, and maybe we should have seen this coming.

2. Victor Martinez, -1.2
SHSTC Index: 35
Martinez missed last year with a torn ACL. He apparently gripped his bat with that ACL, too, because Martinez is awful right now. He's hitting .235/.289/.346 with limited power.

It's weird to think of a guy like this, who is 34 and has never struggled to hit a baseball in his life. Never. Not when he was school-age, not when he was a teenager in Venezuela, not when he was in the low minors, high minors or in the majors. Now he's struggling to hit. That has to mess with him.

Not sure we could have seen this coming, either. He had a pretty good season before he was hurt and the knee injury shouldn't have affected his ... everything, anyway. The year off could have, I suppose.

1. Starlin Castro, -1.4
SHSTC Index: 20
The least-valuable hitter in baseball, at least according to this metric. This one broke the SHSTC.

Castro is just 23 and, heading into this season, he was a career .297/.336/.425 hitter. Flawed, but good. His OPS+ was 104 over his first 1,900 plate appearances. A list of players with a 100 OPS+ over 1,500 plate appearances before turning 23 is too long to put here (40 names), but it's here if you're interested, and it's filled with great names. From 1940 through 1959, six players did it: Ted Williams, Eddie Mathews, Mickey Mantle, Hank Aaron, Al Kaline, and Frank Robinson.

Of course, those guys all blew past the 100 OPS+ mark so that's unfair to Castro. But the players who just squeaked by were pretty good, too: Adrian Beltre, Rusty Staub, Roberto Alomar. Add in that Castro was playing a premium position, and he looked like he was on something of a Hall of Fame path, if something like that exists for someone in his early 20s.

He's probably fine. But as Al Yellon at Bleed Cubbie Blue notes, the Cubs are trying to turn Castro into something he might not be and the results have been disconcerting, to say the very least.