# Predicting pitchers’ strikeouts using xK%

Expected strikeout rate, or what I will henceforth refer to as “xK%,” is exactly what it sounds like. I want to see if a pitcher’s strikeout rate actually reflects how he has pitched in terms of how often he’s in the zone, how often he causes batters to swing and miss, and so on. Ideally, it will help explain random fluctuations in a pitcher’s strikeout rate, because even strikeouts have some luck built into them, too.

An xK% metric is not a revolutionary idea. Mike Podhorzer over at FanGraphs created one last year, but he catered it to hitters. Still, it’s nothing too wild and crazy like WAR or SIERA or any other wacky acronym. (A wackronym, if you will.)

Courtesy of Baseball Reference, I constructed a set of pitching data spanning 2010 through 2014. I focused primarily on what I thought would correlate highly with strikeout rates: looking strikes, swinging strikes and foul-ball strikes, all as a percentage of total strikes thrown. I didn’t want the model specification to be too close to a definition, so it’s beneficial that these rates are on a per-strike, rather than per-pitch, basis.

The graph plots actual strikeout rates versus expected strikeout rates with the line of best fit running through it. I ran my regression using the specification above and produced the following equation:

xK% = -.6284293 + 1.195018*lookstr + 1.517088*swingstr + .9505775*foulstr
R-squared = .9026

The R-squared term can, for easy of understanding, be interpreted as how well the model fits the data, from 0 to 1. An R-squared, then, of .9026 represents approximately a 90-percent fit. In other words, these three variables are able to explain 90 percent of a strikeout rate. (The remaining 10 percent is, for now, a mystery!)

In order for the reader to use this equation to his or her own benefit, one would insert a pitcher’s looking strike, swinging strike and foul-ball strike percentages into the appropriate variables. Fortunately, I already took the initiative. I applied the results to the same data I used: all individual qualified seasons by starting pitchers from 2010 through 2014.

The results have interesting implications. Firstly, one can see how lucky or unlucky a pitcher was in a particular season. Secondly, and perhaps most importantly, one can easily identify which pitchers habitually over- and under-perform relative to their xK%. Lastly, you can see how each pitcher is trending over time. Every pitcher is different; although the formula will fit most ordinary pitchers, it goes without saying that the aces of your fantasy squad are far from ordinary, and they should be treated on an individual basis.

(Keep in mind that a lot of these players only have one or two years’ worth of data (as indicated by “# Years”), so the average difference between their xK% and K% as a representation of a pitcher’s true skill will be largely unreliable.)

It is immediately evident: the game’s best pitchers outperform their xK% by the largest margins. Cliff Lee, Stephen Strasburg, Clayton Kershaw, Felix Hernandez and Adam Wainwright are all top-10 (or at least top-15) fantasy starters. But let’s look at their numbers over the years, along with a few others at the top of the list.

Kershaw and King Felix have not only been consistent but also look like like they’re getting better with age. Wainwright’s difference between 2013 and 2014 is a bit of a concern; he’s getting older, and this could be a concrete indicator that perhaps the decline has officially begun. Darvish’s line is interesting, too: you may or may not remember that he had a massive spike in strikeouts in 2013 compared to his already-elite strikeout rate the prior year. As you can see, it was totally legit, at least according to xK%. But for some reason, even xK% can fluctuate wildly from year to year. I see it in the data, anecdotally: Anibal Sanchez‘s huge 6.7-percent spike in xK% from 2012 to 2013 was followed by a 5.5-percent drop from 2013 to 2014. Conversely, David Price‘s 5-percent decrease in xK% from 2012 to 2013 was followed by an almost perfectly-equal 5-percent increase from 2013 to 2014. So the phenomenon seems to work both ways. Thus, perhaps it shouldn’t have come as a surprise when Darvish couldn’t repeat his 2013 success. To the baseball world’s collective dismay, we simply didn’t have enough data yet to determine which Yu was the true Yu. I plan to do some research to see how often these severe spikes in xK% are mere aberrations versus how often they are sustained over time, indicating a legitimate skills improvement.

I have also done my best to compile a list of players with only one or two years’ worth of data who saw sizable spikes and drops in their K% minus xK% (“diff%”). The idea is to find players for whom we can’t really tell how much better (or worse) their actual K% is compared to their xK% because of conflicting data points. For example, will Corey Kluber be a guy who massively outperforms his xK% as he did in 2014, or does he only slightly outperform as he did in 2013? I present the list not to provide an answer but to posit: Which version of each of these players is more truthful? I guess we will know sometime in October.

Name: [2013 diff%, 2014 diff%]

And here some fantasy-relevant guys with only data from 2014:

# A: No, Jon Lester is not an ace

ESPN’s David Schoenfield asked a timely question yesterday: Is Jon Lester really an ace?

Timely, because not yet reading Schoenfield’s piece (which was posted two hours prior), I wrote this in one of my fantasy league’s message boards:

Unfortunately, Schoenfield made a lot of points I would have liked to make, most of them concerning overall value. Some of it concerned innings pitched. These kinds of things matter in fantasy, but not as much. Sometimes, innings can be harmful, in the sense that a pitcher who eats up a lot of your innings with bad starts, given your league has an innings cap, could do you more harm than good.

But I want to take a step back and look at it through a simpler lens. Lester had the 46th-best WHIP, arguably the best indicator of probably success among the traditional metrics, among qualified starters in 2011 before MLB.com ranked him No. 61 overall in their pre-2012 rankings. And, as Schoenfield states, his ERA ranked 34th. I’m more or less trying to paint the picture of a player who is perennially overrated. In fact, for the duration Schoenfield describes (2008 through 2014), Lester ranks 58th in WHIP and 36th in ERA. Maybe I’m misunderstanding the definition of “ace”, but I think if 30 other guys could be another team’s number-one, you shouldn’t be considered an ace.

The important distinction to make is a lot of those guys who were once good now suck, and Lester continues to be relatively good. For example, Roy Halladay, Dan Haren and Josh Johnson, among many, many others, were once considered top-shelf fantasy goods. That doesn’t really help Lester’s case, though, given a new wave of talented young pitching has completely changed the fantasy pitching landscape, at least in the short-term. Lester’s 2014 season, absolutely his best season by leaps and bounds, culminated with a 2.46 ERA and 1.10 WHIP — good for only 8th- and 16-best, respectively, among qualified starters.

So: Lester’s best year saw him barely scraping the top-10 threshold — at age 30, no less.

So: His strikeout rate soared and his walk rate plummeted. Are these gains even sustainable?

In his defense, he posted career bests in the following metrics: strike percentage, first-pitch strike percentage, 0-2 count percentage, 3-0 count percentage, number of three-pitch strikeouts. These are all things I would expect to see from a pitcher who just notched his best season. In fact, three of these statistics — strikes, first-pitch strikes, 3-0 counts — have all been trending in the right direction for at least four years. That doesn’t necessarily mean Lester can improve upon, or even merely repeat, his success.

The reason I’m concerned in the first place is my projections rank Lester 35th overall, with a 3.66 ERA and 1.26 WHIP. That is, it expects some severe regression.

I don’t think it will be that severe. Lester is a good pitcher, and he obviously knows how to make adjustments. He always seems to post a good ERA no matter how many runners he lets on base, but he also benefited from MLB’s 4th-best defense from 2008 through 2014. Granted, he moves to a Chicago team that ranks 8th (aka marginally worse) in that same time span. Unfortunately, that same Cubs defense plummeted to 17th overall last year, notching a below-average mark. (You can Corey Kluber and the rest of the Indians’ rotation why defense is important.)

And even Lester’s strikeout rate outperformed his peripherals by about 1.8 percent — that is, there’s reason to believe his strikeout rate should have been almost 2 percent lower in the first place, especially given that his strikeout rate was about even with his expected rate the past two years (about five-hundredths of a percent lower than expected, equivalent to half a strikeout each year).

Note: I will discuss expected strikeout percentage in an upcoming post.

My projections expect him to maintain most of the gains in strikeouts (21.0 percent) but for the walk rate to fall back in line with career norms. That sets him up for perhaps an above-average year compared to Jon Lester but a way-below-average year in terms of talking about aces, whether in fantasy or reality.

If you’re in a keeper league, you probably got him relatively cheap — and if you didn’t get him cheap, you can now cover yourself by lying and saying you saw it coming — so keeping him with the hopes of a repeat may not come so steep. But I anticipate Lester being even more overvalued than he usually is, and I will be avoiding him like the plague.

# An impossibly hot stove and an embarrassingly long absence

The stove is hot, people. HOT! And as Every Time I Die once said: I been gone a long time. Sorry about that. I finished the first term of my last year of graduate school. It was probably the hardest one, and it should be smooth sailing from here on out.

I’m also pretty proud of a research paper I just completed regarding the probability of future success of minor leagues. The results are robust and I couldn’t be more pleased. It was a school project, so I didn’t have time to make it nearly as complex as I would have hoped, but it’s something I plan to further investigate in the coming days, weeks, months, what-have-you.

Anyway, there is plenty of news flying around as well as plenty of analysis. I’ll do my best to recap, but surely I’ll miss some things:

And I’m ignoring all the prospects involved as well. Marcus Semien, Austin Barnes, Jairo Diaz and others got shipped. I can only imagine a whole lot more action will be happening soon, as there still are teams with surpluses and deficits at all positions and some big-name free agents left on the market, including Max Scherzer and James Shields.

It is clear, however, that the Cubs  and Blue Jays intend to more than simply contend. I would say the Marlins intend to as well, but I don’t even think they know what they’re doing, let alone we do. The White Sox are looking like a trendy sleeper with some key pitching additions (LaRoche is also an addition, but far from what I would call a “key” one), but they are far from a championship team.

But with so much more yet to happen, maybe it’s best to wait and see. There are obviously some ballpark and team-skill implications that will affect all these players’ projections, but I’ll get around to those in 2015.

I’ve finished my preliminary set of pitcher projections. I’ll share them but they’ll see some refining by the time March rolls around.

I’m also looking at how my projections fared last year. That will come in the next couple of days.

Keep your ear to the ground, people. Or to the stove. Never mind. Terrible idea. You’ll burn yourself. Just keep it to the ground.

# What did and didn’t work this year

A part of me feels like I need to provide some credentials if I’m dishing out fantasy advice. I’ve been waiting all year just to see if following my own advice would pay off. I played in four leagues, and the results are in:

1st place – 10-team roto, auction (League of Women Voters)
1st place – 10-team H2H roto, snake
2nd place – 10-team H2H points, snake
3rd place – 10-team H2H points, snake

The most important victory to me is the first one, in the League of Women Voters, a league in which a bunch of my dad’s friends have been playing for decades. I want to look back and 1) try to remember my exact draft strategy; 2) see how well I adhered to it; and 3) see where I went wrong.

I went into the draft knowing I would target a very specific and short list of players. This did not allow a lot of room for flexibility, although I did leave a couple of outfield spots open that I would fill on the fly. I can tell you right away I wish I was stricter on those last two outfield spots. I also did not target any specific category, although I did punt saves for the most part. Although I simultaneously led every offensive category except for stolen bases for most of the summer, it became obvious to me that I accidentally loaded up on batting average and undervalued steals.

What I did right:

• \$1 for Yan Gomes. I guaranteed Gomes would be a top-10 catcher with the chance to break the top 5; he finished No. 4 on ESPN’s player rater. (I also drafted Victor Martinez, and once he gained catcher eligibility, I dropped Gomes. It happened early in the season — too early for me to know better — but I wish I hadn’t.)
• \$16 for Jose Abreu. There’s no way I knew he’d be this good, but after snatching up Yoenis Cespedes off of free agency in the first week of 2012 and drafting Yasiel Puig to my bench in 2013, I pledged to gamble as much as \$20, maybe more, on the MLB’s most recent Cuban import.
• \$13 for Martinez. I think he’s perpetually underrated, but I can tell you that not a single person in the world knew V-Mart would hit 30 home runs, let alone 20. I won’t pat my back on this one. I normally wouldn’t keep him, but I may have to in the off-chance he’s pulling a late-career Marlon Byrd on us (in terms of power, that is).
• \$1 for Corey Kluber. My love for Kluber is well-documented. I tempered my expectations and slotted him as my No. 32 starting pitcher, but I vastly underestimated his innings total (45 more innings than I projected), his wins (17 to 10) and, of course, his strikeouts (10.3 K/9 to 8.4 K/9). But I’m glad I took a conservative approach; the most important takeaway is that Kluber clearly exhibited the talent to be at least a middle-tier fantasy starter with upside. And boy, did everyone underestimate that upside.
• \$11 for Cole Hamels. I liked this play at the time, and I still do: I waited maybe a month to get a potential top-10 starter at about half-price. He’s a possible keeper next year (\$14 on a \$260 budget), but the Phillies’ inability to help him reach double-digit wins is troubling.
• \$2 for LaTroy Hawkins. He’s terrible, but at least I wasn’t the idiot who overspent on the perpetually inept Jim Johnson. How he lucked into more than 100 wins in two seasons is beyond me.

What I did wrong:

• \$51 for Miguel Cabrera. It was the most a player had ever gone for in the league, at least since the Rickey Henderson days. It was hard to predict such a massive drop-off in power — maybe 30 home runs was understandable, but only 25? — and I didn’t leave myself any room for savings. That is, I paid full price instead of looking for bargains, the latter of which was my game plan from the start.
• \$37 for Ryan Braun. An even worse bid, in hindsight, and another instance of paying full price instead of finding the bargain.
• \$10 for Everth Cabrera. Cabrera was a keeper, and he may have gone for more at auction. But wow, what a bust. Again, tough to see something like that coming, especially such a steep decline in on-base percentage.
• \$10 for Brad Miller. I made a bold prediction about Miller before the season started. I think the only thing more amazing than his plate discipline completely vanishing is how much owners in my league were willing to spend on a largely unknown quantity. I really thought I was being sneaky on this one, especially so late in the draft. This was a case in which I was too sold on a guy to budge and take a different name — especially when Dee Gordon and Brian Dozier were still on the board.
• \$12 for Shane Victorino. Was 2013 a flash in the pan or what? I don’t know if this guy’s legs will ever be the same again.

I’m excited to start preparing my projections for next year. I have made some revisions, tweaked some formulas… I’m looking forward to how the projections turn out.

And now I have a concrete idea in my head of how I should approach my ideal draft.

# Blind résumé: thoughts on perceived value

Fantasy analysts say things like, “I know, I know, blind résumés are cliché,” and then proceed to do them anyway. So.

I know, I know, blind résumés are cliché. But this is important, I swear. This is an exercise in perceived versus actual value, and exploiting market inefficiencies.

Note: I wish I had written this a month and a half ago (June 21, to be exact), when I talked about it with my good friend/league enemy Rob. You’ll see why.

OK, here are the stat lines, as of Sept. 5:

Player A: 81 R, 16 HR, 73 RBI, 6 SB, .301/.351/.458/.808
Player B: 73 R, 13 HR, 60 RBI, 8 SB, .295/.382/.481/.864

If we are talking about players’ offensive skills from a traditional standpoint, you can argue that Player B is perhaps more valuable, given the comparable batting average, better on-base percentage and better isolated power (ISO). However, this is a fantasy baseball blog, and Player A is clearly the more valuable one as he leads all categories except stolen bases.

The screenshot is from a pre-trade deadline conversation I was having with Rob. And if you haven’t caught on by now, Player A is Melky Cabrera, and Player B is Yasiel Puig. I set the blind résumé deadline at Sept. 5, marking Cabrera’s last game prior to missing the rest of the season with a finger injury.

Referring back to the side note at the beginning: On June 21, ESPN’s Tristan H. Cockcroft ranked Puig in his Top 10 and Cabrera outside his Top 50. At the time, the blind résumés would have looked more like this:

Cabrera: 47 R, 11 HR, 38 RBI, 4 SB, .300/.345/.476/.821
Puig: 39 R, 11 HR, 44 RBI, 7 SB, .321/.411/.538/.949

Honestly, their stat lines were less similar than they are now. Anyway, the important part to note is Cockcroft’s updated ranking are always going-forward rankings — that is, Puig will be a Top-10 player going forward. And on June 21, Cockcroft thought Puig was the 8th-best fantasy option available (Cabrera, meanwhile, 65th or so) despite him going almost a month without clearing an outfield fence.

Things have changed, obviously. Cabrera was the better player in all categories since June 21 — in fact, his triple-slash rates are almost identical more than two months later, serving as a testament to his consistency — and his fantasy contributions have dwarfed those of Puig. Still, Cockcroft ranks Puig the No. 14 outfielder (40th overall) and Cabrera No. 20 outfielder (62nd overall). Elsewhere, CBS Sports’ Al Melchior still lists Puig as his No. 4 outfielder. (He has omitted Cabrera from his list given the news of his injury.) Michael Hurcomb, also of CBS Sports, lists Puig as his No. 4 outfielder and Cabrera at No. 15. (His list was last updated Aug. 12, but it’s not like Puig wasn’t already slumping.) Only one of the three CBS Sports analysts, Scott White, seems to have some sense, ranking Cabrera above Puig (Nos. 11 and 15, respectively).

Perhaps Puig is due to bounce back from a prolonged slump, which would justify his high ranking. But he had sported an abnormal BAbip (batting average on balls in play) all year; and while his 2013 BAbip was a monstrous .383, it would be wildly impressive for him to possess the hitting prowess to sustain one of the highest BAbips in MLB history. So, now, Puig owns a .353 BAbip, still well above the league average.

The question now: Is Puig a premium hitter, or has he been the beneficiary of a lot of good luck for a long time? ESPN’s hard-hit average data would be very beneficial right now, but alas, I don’t have access to it. Line drive rates can be used as a theoretical comparison, however, albeit not a pure substitute: line drives epitomize hard contact. And Puig has hit line drives only 14.3 percent of the time this year, as opposed to 19.1 percent of the time last year. (Mike Trout, who has seen his BAbip fall a comparable 31 points in BAbip from 2013, has seen his line drive rate drop an equally-comparable 4 percent.)

It will take a larger sample size — namely, the addition of the 2015 season — to determine whether Puig is closer to his 2013 line drive rate or his 2014 rate — and, thus, whether he is closer to his 2013 BAbip or his 2014 BAbip. For now, I would err on the side of caution and bank on the floor rather than the ceiling.

All of this slowly gets me back to my point: People have different perceptions of players’ values, and they often let other factors inhibit their judgments, even subconsciously. For example, people may still attribute Cabrera’s success to PEDs, a worry which seemed to be validated by his sub-optimal 2013 (during which he played through a herniated vertebrae, or something like that). Meanwhile, Puig is the next big thing, and people expect such from him. When you strip them of their names — from which their discrepancies in value stems, honestly — you uncover the market inefficiency lying within.

Not that I can say that I would have had the foresight to trade Puig for Cabrera on June 21 (mostly because I owned both), but if I was offered Puig for, say, Corey Dickerson, straight up, I would have pulled the trigger. Because at that point, it was all about name value and recognizing the true performance of each player without bias. Dickerson, having arguably a better season than Cabrera or Puig, is ranked Nos. 17, 25, 32 and 40 among all outfielders on the four expert lists I mentioned.

Moral of the story: Try not to let the name bias your projections. Exploit other owners’ misguided perceptions of value.

# V-Mart, Abreu could join elite 30/.330 club

This morning, ESPN’s David Schoenfield mentioned that the Detroit Tigers’ Victor Martinez is baseball’s best hitter, leading all of Major League Baseball in wOBA (weighted on-base average) and wRC+ (weighted runs created plus), which measures a player’s offensive contributions after controlling for park effects. It’s a shame he won’t earn many American League MVP votes — I wouldn’t be surprised if teammate and former MVP Miguel Cabrera blindly earned more — simply because he contributes little to no defensive value.

Still, V-Mart is batting .337 with 30 home runs, setting him up to be part of an elite club. It’s not a popular one, mostly because it doesn’t have a flashy name or fancy title, but it is still very much meaningful: The 30-HR, .330-BA Club.

There have been only 62 such seasons in the past 50 years. There are repeat offenders, however, so the club actually consists of only 37  hitters dating back to 1964.

And the names in this club are not nobodies. Cabrera. Albert Pujols. Todd Helton. Frank Thomas. Vladimir Guerrero. Chipper Jones. The list goes on. It’s a group of men that consists of seven Rookies of the Year and three Hall of Famers (and more to come) and has collected 31 MVP awards and 244 All-Star nods. The inclusion of Martinez and perhaps Chicago White Sox first baseman and Cuban rookie sensation Jose Abreu, who currently sits at 33 homers and a .317 average, would add another six All-Star berths and possibly another Rookie of the Year.

This is nothing more than a cool historical footnote. It doesn’t really feel like we are witnessing history because fans have witnessed 39 such seasons of 30/.330 since 2000, and Martinez’s teammate Cabrera has achieved the feat each of the past three years on his own. Still, when we discuss seasons of truly amazing hitting — commending not only a player’s power but also his incredible plate discipline and coverage — Martinez’ (and Abreu’s) names should be included in the conversation. And maybe it’s just me, but given Martinez’ age and career trajectory, his inclusion on the list will certainly be surprising — and impressive.

The comprehensive list (1964-2013), with number of times each player achieved 30/.330, is listed below.

5 times
Albert Pujols

4 times
Barry Bonds
Manny Ramirez
Todd Helton

3 times
Frank Thomas
Larry Walker
Miguel Cabrera
Mike Piazza

2 times
Gary Sheffield
Jason Giambi

1 time
Albert Belle
Alex Rodriguez
Billy Williams
Bret Boone
Carlos Gonzalez
Chipper Jones
Dante Bichette
Dave Parker
David Ortiz
Derrek Lee
Don Mattingly
Ellis Burks
Fred Lynn
George Brett
Ivan Rodriguez
Jeff Bagwell
Jeff Kent
Josh Hamilton
Lance Berkman
Matt Holliday
Mo Vaughn
Moises Alou
Ryan Braun
Tim Salmon (Salmon is the only player on the list without an All-Star Game appearance. He achieved the feat in 1995, hitting .330 with 34 HR and a 1.024 OPS. He won Rookie of the Year honors in 1993 alongside Piazza.)

Another month without any published material has come and gone. Meanwhile, Matt Shoemaker earned himself American League Pitcher of the Month and Rookie of the Month honors for August. Good thing I wrote my glowing endorsement for him on July 25. It will be interest to see how he’s ranked next year. Julio TeheranMichael Wacha, Sonny Gray and Tony Cingrani were touted prospects and drafted Nos. 29, 32, 41 and 44 on average in ESPN live drafts this year after pretty amazing 2013s. So, what now for Shoemaker? He was never a touted prospect; most fans still probably don’t know who he is, similar to how I anticipate Corey Kluber will get robbed of Cy Young votes this year simply because he isn’t a name-brand ace.

Alas, there will be doubts about Shoemaker’s ability to repeat his performance — his swinging strike and contact rates have tailed off a bit since I wrote about him a month ago, and he doesn’t occupy the strike zone enough for me to think the walk rate is sustainable — which could make him a 2015 draft day bargain. Starting pitching is deeper than ever, so it would not surprise me whatsoever to see Shoemaker make a variety of “just missed” lists, right outside the Top 60 pitchers or so, with an average draft positions of maybe 45th for starting pitchers.

If I had to run a quick-‘n’-dirty projection for next year right now, it would look something like:

Bearish: 180 IP, 11 W, 3.15 ERA, 1.20 WHIP, 160 K
Bullish: 200 IP, 13 W, 2.94 ERA, 1.13 WHIP, 189 K

FYI, those are both pretty darn good projections, good for what will probably be Top-30 in my 2015 rankings.

Anyway. ANYWAY.

Let’s get to what I really wanted to discuss: 2015 fantasy prospect sleepers. Many notable prospect lists are published prior to the start of each season, and a handful are updated as the season unfolds. Case in point, ESPN’s Keith Law published his updated Top 50 list about a month ago. Obviously, the list accounts for the triumphs — and tribulations — of current and now-former top prospects in whichever league(s) the player performed this season as of July 17.

Today’s scouting report has two faces: the qualitative, through which we award players a grade of 20 through 80 for their five tools; and the quantitative, through which we assess the progress of a player based on what he has actually accomplished.

It’s all good and well that prospect lists exist — especially updated ones. But, frankly, there isn’t room on the list for everyone, and the lists often span more than just players who are Major League-ready.

Thus, I occasionally look at Minor League leaderboards and try to find less-trendy fantasy prospects to scoop in the late rounds of a draft or spend a dollar on in the twilight of an auction. I create a list and periodically update it, tracking the player’s progress or lack thereof.

In alphabetical order, here are some players who, given playing time, could be impact players in 2015:

Steven Moya, DET OF | 40 Hit, 60 Power, 50 Run (MLB.com)
It wouldn’t surprise me if 99 percent of baseball fans outside of Michigan knew Moya was called up when the Tigers’ roster expanded. Absent from all major prospect lists, Moya belted 35 home run, swiped 16 bases and batted .276 in 133 games at Double-A Erie. Those are numbers that could get anyone all hot and bothered. It’s not a huge surprise to me why he wasn’t so highly touted: he combined for only 42 home runs and 16 stolen bases combined in his first four years in the minors. What’s overlooked, though, is he debuted when he was 17, and he has obviously made great strides as he fills out at the ripe age of 22. All that glimmers is not gold, however; Moya struck out in almost 30 percent of plate appearances while walking only 4 percent of the time. There’s a lot of potential for bust simply because he may never catch up to Major League pitching.

Looking forward: Moya is currently buried on the depth chart, as he was called up more for depth and reps than impact contributions. Still, right fielder Torii Hunter‘s contract expires this year, leaving Moya to compete with Rajai Davis, J.D. Martinez and Ezequiel Carrera (whom I actually like as a speedy, Leonys Martin-type of outfielder). Davis is underrated and Martinez has reestablished himself as a credible starter, although it remains to be seen if he sustains it, but I would not be the least bit surprised to see Moya win a starting role over Carrera — or all of them, really. His plate discipline is problematic, though; even notorious free-swinger Pedro Alvarez had better discipline before his call-up. Still, not all prospects with poor hit tools are doomed to bust, but given his relatively unknown prospect status — he’s buried at No. 7 in the Tigers’ organizational depth, according to MLB.com — he could be a low-risk, high-reward (and also high-volatility) player in 2015.

Steven Souza, WAS OF | 40 Hit, 50 Power, 50 Run (MLB.com)
Souza is perhaps the most talented and enigmatic of the three players listed here, based strictly on 2014 performance and MLB.com’s scouting grades. Like Moya, Souza didn’t make any preseason or midseason top-prospect lists, despite hitting 18 home runs, stealing 26 bases and batting a whopping .350 across 407 Triple-A plate appearances. (In there defense, Souza was really, really bad prior to 2012, and was busted for PEDs in 2010.)

Again, if you live outside of New England and knew Souza was recently called up when rosters expanded: congratulations! All of Souza’s numbers — his speed, his power and especially his hit tool — correlate very poorly with how MLB.com evaluated him above. Even if the power and speed do somehow project to be average, his plate discipline is very evidently better than below-average: he struck out in 18.4 percent of plate appearances and walked in 12.8 percent of them. And he achieved this in Triple-A, not Double-A, where Moya flailed away. Future Cleveland Indians shortstop Francisco Lindor allegedly has a 70-hit tool, yet posted strikeout and walk rates of 19.5 and 5.2 percent — not at all elite. Trust the statistics.

Looking forward: The only things standing between Souza and a starting role in 2015 is Denard Span‘s 2015 team option (who has performed well enough to earn it and then some) and the next guy on this list. Thus, Souza may be doomed to a fourth-outfielder role next year until Bryce Harper inevitably injures himself, so Souza’s heyday may not truly come until 2016. If he somehow assumes the first baseman role, it would be hard to rely on a guy who hits 15 home runs, steals 10 bases, bats .275. But if he eventually moves to the outfield where he belongs, or gets traded, his potential /.280/.340/.380 would be serviceable in fantasy leagues.

Michael Taylor, WAS OF | 40 Hit, 50 Power, 60 Run (MLB.com)
Shoot. I kind of forgot that Taylor and Souza are on the same Triple-A team battling for the same potential center-field opening that will, realistically speaking, not be vacated by Span next year. Taylor got a brief look earlier in the year and promptly hit a home run — but also struck out eight times in 22 trips to the plate. It’s difficult to ignore his 22 home runs, 34 stolen bases and .313 average at Double-A Harrisburg, and the 51 steals at Single-A Potomac last year add a nice touch. Like Moya, the hit tool as graded by MLB.com is probably accurate: Taylor struck out 130 times in 441 plate appearances (25 percent), but at least he walked more than the league average.

Looking forward: Taylor and Souza are theoretically competing with each other, which could make either of them offseason trade bait. Taylor, however, spent the majority of this year in Double-A, only recently getting promoted, so he may have a year of development ahead of him, despite being ahead of Souza on MLB.com’s organizational depth for the Nationals (Nos. 5 and 7). It’s also worth noting  that Souza is listed as third on the depth chart at first base, and Adam LaRoche is in the final year of his contract, so it’s possible that Taylor earns the fourth-outfielder role and Souza earns first base outright (or becomes the backup to Kevin Frandsen… yuck). Ultimately, it’s hard to ignore any potential 20/20 players, and he looks like another guy who could get there, albeit with a low batting average.

If I had to guess which of these three players will make the biggest impact in 2015, I would say Moya, who I think has the highest bust potential but also the highest ceiling. Souza is the safest and will make for an adequate, and perhaps enticing, replacement given the event of an injury in the Nationals’ outfield. Taylor has the same kind of boom-or-bust potential as Moya, albeit with a little less power and a little more speed.