The Long Game: Buying High

Wait, that's not right. Isn't it supposed to be "sell high" and "buy low"?

Well, in an ideal world, sure. You trade your assets at their peak, acquire players at the exact moment they've hit rock bottom and are about to rebound, and ride those value waves all the way to a dynasty. The real world is rarely so neat and tidy, though, and it's that messiness that can create some opportunities.
Every year, there are players that get off to big and surprising starts. Sometimes they fade back into obscurity afterwards, but sometimes those early returns signal that the player has made some change to their approach or simply matured, and they are rapidly establishing a new baseline for their future performance. Ask anyone who "sold high" on Jake Arrieta in 2014 after his 1.95 ERA before the All-Star break, or on Jose Bautista after he cranked 16 home runs in the first two months of 2010, if they'd like a do-over on those deals.

Now, you're not going to get any of these players cheap, and there's no guarantee that any of them will become anything close to the next Bautista or Arrieta. But when there are strong statistical indicators that a player's breakout performance might be sustainable, it can still be worthwhile to try and trade for those players, as their current owner might think they are "selling high" on an unsustainable performance, but still be asking less than the player's ultimate value based on their new level of production. In fact, the best way to approach trading for these players is not as part of a rebuild, but as part of a title run. Offer a team lower in the standings an established prospect for one of these early-season flukes, and they might think they're winning the deal by turning found money into a more stable asset. If the fluke turns out to be not so fluky, though, you've not only strengthened your roster for a championship run in the short term, but acquired a foundation piece for your future rosters as well.

Brandon Belt, 1B, Giants: Belt is almost the perfect buy-high guy. He's been around long enough that people have a set idea of who he "really is", making it easier to write off a hot start as a fluke. He's still just 28 years old, though, and it's entirely possible that he's found another level to his game. His .311/.440/.521 line certainly isn't a product of mere good luck, as his .347 BABIP is actually lower than last year's .363 and his 9.5 percent HR/FB is also lower than his 13.6 percent from last season. The big changes are in his plate discipline. Belt's 18.7 percent walk rate and 14.7 percent strikeout rate are elite, and miles better than 2015's 10.1 percent and 26.4 percent respectively. Basically, Belt is doing the same amount of damage or even a bit less when he hits the ball in 2016, he's just hitting it a lot more often. Those are strong signals that his approach has improved, and that's the kind of thing that turns good hitters into great ones.

Jackie Bradley, OF, Red Sox: As I write this, Bradley has reeled off five straight multi-hit games with three home runs and 14 RBI, so "buying high" may even be an understatement. He's also been red-hot for stretches in the past, hitting .354/.429/.734 last August but still winding up with a weak .249/.335/.498 slash line on the season. That history of high peaks and crushing valleys might be exactly the thing to encourage anyone currently rostering him to part with the 26-year-old now, while the roller coaster is on the ascent. The 2016 edition of Bradley looks much better at the plate than the 2015 version, however. His strikeout rate is up (22.7 percent versus 27.1 percent last year) thanks to an increased contact rate (74.1 percent after 71.5 percent in 2015), and he's not just making more contact, but more hard contact (40.9 percent versus 32.1 percent last season). His 21.4 percent HR/FB will probably tick downward, but otherwise there are strong signs that he's become a much better hitter than his career .230/.302/.387 line, or even last year's performance, would indicate.

Nick Castellanos, 3B, Tigers: Castellanos has been mediocre for so long, it's becoming hard to remember a time when he was the crown jewel of the Tigers' farm system. He's still just 24 though, and after hitting a career-high 15 homers last year he's already halfway to match that total through six weeks in 2016. On the surface, there isn't a lot to suggest his surge is sustainable. His walk rate (5.6 percent) and strikeout rate (23 percent) are right around where they've been for the past couple of seasons, and his .422 BABIP will tumble. However, there's been a radical change in his batted ball profile that bodes well. In 2015, his GB/FB/LD rates were 36.2/40.4/23.3 percent, but this year he's hitting the ball with a lot more authority, posting rates of 21.1/47.8/31.1 percent. A visual examination backs up those numbers, as his weight transfer and swing plane are geared much more towards putting the ball in the air than they were when he got to the majors. It's almost like being able to learn from Miguel Cabrera and J.D. Martinez has had a positive effect on the kid's swing. His 16.3 percent HR/FB is much improved but hardly outrageous, and more balls hit in the air and hit harder suggests that while his batting average gains aren't sustainable, his power spike very well might be. If Castellanos comes out the other side of his hot start as a .260-.270 hitter with 25 HR pop, he'll be an asset on any roster.

Aledmys Diaz, SS, Cardinals: The potential for Diaz to be a true breakout instead of a six-week fluke resides more in his odd path to the majors than sabermetrics. A Cuban refugee, he reached the US in 2013 as a 23-year-old and tried to fudge his birthdate by a few months to avoid being subject to MLB's international bonus pool rules. Oops. As a result, his eventual signing was delayed and when he finally signed with the Cardinals' in early 2014 it had been 18 months since he'd seen any game action. A shoulder injury prevented him from shaking off too much rust, and he actually got dropped from the 40-man roster in 2015 after a slow start. Finally healthy and comfortable, he exploded in the second half last year and has carried that momentum straight to the majors. With all that noise in his short minor league track record, it's tough to tell what Diaz's ceiling might be. His .391 BABIP will almost certainly drop but he's shown flashes of plus contact ability before, posting a .341 BABIP in 34 Double-A games in 2014 and a .372 BABIP in 14 Triple-A games last year. Even if he can sustain a BABIP around .320 in the majors, his batted ball profile suggests he'll be able to maintain a batting average in the ballpark of .300 thanks to a low strikeout rate (9.6 percent), and his .271 ISO might not be that inflated either. A middle infielder who can hit .300 with solid power is gold in the modern fantasy era, and that's what you could be getting.

Brett Lawrie, 2B, White Sox: As a 26-year-old former top prospect, it's really easy to convince yourself that Lawrie has turned a corner this season. He's seen a big spike in his walk rate so far (a career-high 12.4 percent after just 4.7 percent last year) and his power surge is due to him hitting the ball in the air more often, as 2015's 48.8 percent groundball and 32.7 percent flyball rates have essentially flipped, giving him 33.3 percent GB and 49.4 percent FB rates. It's not all rainbows and cupcakes for Lawrie of course, because it never is with him. His .395 BABIP will probably dwindle, and even if it doesn't his career-high 31 percent strikeout rate will put a hard cap on his batting average, but at the very least this looks like the year Lawrie breaks through for 20-plus home runs.

Chris Tillman, SP, Orioles: After a solid half-season in 2012, Tillman put together two decent but underwhelming campaigns the next two years that weren't really backed up by his peripherals. Then in 2015 his numbers collapsed pretty much across the board, landing him on a lot of fantasy players' Do Not Want list. Now he seems back to his 2013-2014 form, but is it a mirage? Is another 4.99 ERA lurking just as soon as you buy in? Actually, all signs point to Tillman's 2016 success being somewhat sustainable despite his track record. His fastball velocity of 92 mph is the highest it's been since 2012, but he's also throwing it a lot less while leaning more on a cutter for added deception. The result is a career-high swinging strike rate of 10.9 percent and career-low 75.3 percent contact rate, fueling his 25.8 percent strikeout rate, which is better than a four percent jump on his previous best in the majors. Tillman's still only 28, so he could just be coming into his own. After watching Arrieta blossom in Chicago and failing to produce a homegrown rotation success story despite having a number of talented arms go through their system, it looks like the O's might finally have an ace (or two, considering Kevin Gausman's 2016 to date as well) to call their own.

On the other hand, there are also some hot starts from players that seem like they could evaporate at any time. At the right price it could still be worth taking a chance on them establishing a new baseline performance level, but it seems more likely that they'll go back to being who we thought they were any second now:

Dexter Fowler, OF, Cubs: The obvious number for Fowler is his .432 BABIP against a career .344 rate, but let's dig a little deeper. It's not just that he's getting more hits when he puts the ball in play, but that he's flat out murdering the ball when he makes contact. His career hard-hit ball rate is 29.8 percent, but this year it's 41.7 percent. Similarly, his career soft-hit rate is 17.2 percent, but this year it's 10.7 percent. It's not like he's pulling the ball more often, either, as his 38.1 percent pull rate is lower than last year's (44.1 percent) and just below his career rate of 39.8 percent. At 30 years old, it's certainly possible that Fowler is developing some opposite-field power, but this seems far more like a good stretch of baseball than a sustainable adjustment.

Daniel Murphy, 2B, Nationals: Yes, Murphy's hot streak dates back to the second half and playoffs last year. His .439 BABIP is still more than 100 points better than his career .322 rate, and an eight percent soft contact rate against a 42 percent hard contact rate is just absurd. Are those sustainable? I honestly don't see how they can be. To put those numbers in perspective, major league home run leader Nolan Arenado has a 44.7 percent hard contact rate against a 13.8 percent soft contact rate, while Murphy's teammate Bryce Harper had rates of 40.9 percent and 11.9 percent in his historic 2015. Maybe Murphy's suddenly become one of the elite power hitters in the game at 31 years old, but if his batting average and power both seem ripe for regression, there's not much room left for him to be much more than the player he was expected to be for the next four months.

Rick Porcello, SP, Red Sox: I want to believe that Porcello is finally blossoming into an ace. I really do. He's still only 27, and it would frankly be hilarious if the "terrible" contract the Red Sox gave him before last season turned out to be a bargain. His career numbers to date have two glaring flaws, however. One, a .250 BABIP is due to rise, perhaps significantly given his career .315 rate. Two, while his career-high 24.9 percent strikeout rate seems outstanding, his 7.5 percent swinging strike rate is right where it's always been. Porcello's additional punchouts have been on called strikes, not swinging ones, which is especially worrying given his career-low 89.8 mph fastball. This is a bubble that seems ripe for bursting once opposition hitters take the bat off their shoulders again.

Tanner Roark, SP, Nationals: The runt of the Nationals' rotation litter, Roark was thought to be just keeping a spot warm for Lucas Giolito after getting dumped to the bullpen last season, but instead he's been lights-out to begin 2016. Like Porcello, though, his extra strikeouts (career-high 22.4 percent strikeout rate) aren't supported by an increased swinging strike rate (8.2 percent, right in line with the 8.4 percent he managed in 2014 in his last stint as a full-time starter). He is using his slider less and his curveball more than he did in 2014, which could help sustain some fraction of his gains, but when hitters are simply swinging less rather than swinging-and-missing more, it usually doesn't bode well for your future performance.