“Those who do not learn history are doomed to repeat it.” That’s the cliché, right? Whoever came up with that was, like John Denver, full of shit. Or at least they never played fantasy baseball.

Our objective here is to learn from the past and hope it repeats itself. The task is to identify potential breakout players in 2018, and to do that we’re going to look at last year’s breakout players. Hopefully we can identify why everyone missed on last year’s surprise players and find the guys poised to follow a similar path.

This Year’s Ryan Zimmerman

Zimmerman had an excellent stretch from 2009 to 2014 where he posted at least a 119 wRC+ in each season. His wRC+ fell to 106 in 2015 and then fell off a cliff in 2016 all the way down to 67. Zimmerman played only a combined 210 games in those two seasons and was entering his age-32 season last year. It’s not hard to see why Zimmerman’s ADP was outside the top 400 in Howard Bender’s Mock Draft Army heading into last season.

As is almost always the case for breakout players, Zimmerman benefitted from some good luck last season. He had career highs in BABIP and HR/FB rate, though his BABIP wasn’t out of line with what he posted during his peak. It was really the power that was the surprise. His 26.5 percent HR/FB rate was almost nine points higher than his previous career high.

Zimm didn’t really change his batted ball profile or anything, he just hit the ball a hell of a lot harder when he elevated. He ranked 10th in average exit velocity among players with 150-plus batted balls last season, and he ranked seventh in average exit velocity on fly balls and line drives.

The two players most likely to fit this mold in 2018 are Mark Trumbo and Carlos Gonzalez. Both are entering their age-32 season, just as Zimmerman was last year, though the similarities go beyond simply age.

Both guys have displayed power in the past, which is a prerequisite to be this year’s potential version of Zimmerman. Trumbo has hit 29 or more home runs in four seasons with a career high of 47, and CarGo has hit 25 or more home runs in five seasons with a career high of 40. They’re also reasonably like Zimmerman in strikeout and walk rates and batted ball profiles.

As mentioned, Zimmerman’s uptick in hard contact was the key to his success last season, and Trumbo has shown the ability to hit the ball hard in the past. We only have average exit velocity from Statcast dating back to 2015, but Trumbo has hit the ball with authority at times in that span. In both 2015 and 2016, Trumbo finished top 10 in average exit velocity among batters with 150-plus batted balls.

As for CarGo, he hasn’t hit the ball with much authority in recent seasons, but he did finish last year strong in that regard. Check out this graph from Baseball Savant showing CarGo’s rolling average exit velocity.

It looks like CarGo may have figured something out late last season and started to hit the ball with authority on a regular basis. In the second half he posted a .390 wOBA, and he had a monster .510 wOBA in September. There’s some speculation that CarGo could end up back in Colorado, which would obviously be ideal. But he’s also been linked to the O’s as a possibility, which wouldn’t result in a huge drop off in home park if he and Trumbo end up being teammates.

Neither Trumbo nor CarGo is going quite as late as Zimmerman was in drafts last year, but they’re still going late enough that they would represent huge values if they end up having anything near the kind of year that Zimmerman has last year. Trumbo has an NFBC ADP of 245, and CarGo is just barely inside the top 300 with an ADP of 283.

This Year’s Cody Bellinger

We’ve got a pretty specific set of criteria when trying to identify the next Bellinger. Prior to last season, Bellinger had all of zero plate appearances above Triple-A, yet he still managed to amass over 500 major league plate appearances and hit 39 home runs. In the lower levels of the minors he displayed some of the pop he would produce in the majors with 30 and 23 home run seasons in near full seasons at High-A and Double-A, respectively.

As you might imagine, 21-year-olds with no experience at Triple-A who immediately come up to the big leagues and hit for .300-plus ISO power are few and far between. It’s unlikely that we’re going to get a Bellinger-type player in consecutive seasons, but even a reasonable approximation of what Bellinger did last season would be a major win for fantasy owners.

The closest thing to pre-2017 Bellinger that we can identify is Baltimore’s Austin Hays (the emphasis on Baltimore hitters in this article was completely unplanned). Hays will be 22 this season, but like Bellinger pre-2017, Hays has yet to see any Triple-A action. But also like Bellinger, Hays projects to make the leap straight from Double-A to the majors. The crowdsourced Depth Chart projections from Fangraphs are projecting Hays to see regular work with a projection of 525 PA.

Assuming Hays gets the workload, he’ll have a shot to produce Bellinger-like numbers. Hays posted an ISO of .264 last season with 32 total home runs as he split the season between High-A and Double-A. For comparison, Bellinger his 30 home runs in a full season at High-A with only 19 fewer PA than Hays had last season. Bellinger did not hit for mas much power at Double-A with only a .221 ISO at that stop in the minors.

The biggest difference between the two players is their plate discipline profile. Bellinger probably has more swing-and-miss in his game than Hays, but Bellinger definitely has more patience. Bellinger struck out 26.6 percent of the time last season, and Hays only struck out 25.4 percent of the time in a 63 PA major league stint at the end of last season. Hays also only struck out at about a 15 percent rate in the minors last year.

On the other end of the spectrum, Bellinger walked at a good clip throughout the minors and then posted a healthy 11.7 percent walk rate in his rookie season. Hays, on the other hand, only walked at about a 4.5 percent rate in the minors last season. It’s good that Hays has a seemingly better ability to make contact when he swings than Bellinger does, but Hays would be well served to add some of Bellinger’s patience to his game. The patience is probably a more relevant skill at the highest level.

Bellinger was going just outside the top 400 in the Mock Draft Army ADP last year, and Hays is currently going 352 in NFBC drafts. Bellinger arguably finished 2017 as a top 30 hitter, and Hays doesn’t have to be nearly that good to return significant value at his current ADP.

This Year’s Scooter Gennett

Of all the 2017 surprising performances that we’ll discuss here, Gennett hitting 27 home runs may well be the most surprising. In three full seasons prior to 2017, Gennett never cracked a .150 ISO and then he pops off a .236 ISO out of nowhere. That said, there’s at least some possible explanation for it.

In 2016 Gennett focused on elevating the ball more, dropping his GB/FB ratio to 1.29 from 1.63 the season prior. He saw some success by doing so, as he hit 14 home runs compared to six the year before. Gennett apparently doubled his efforts to elevate more last season by dropping his GB/FB rate even more down to 1.10.

Gennett most certainly got a little lucky to hit 27 home runs, and elevating more to hit about as many fly balls as you do ground balls is no guarantee that you’re going to hit 25-plus home runs. But if you are going to see an increase in power, it’s a good place to start. Also helping Gennett’s cause was a favorable home ball park as Cincinnati was the fourth most homer-friendly park for left-handed hitters last season.

The formula here is simple. We’re looking for a guy (or guys) who started to elevate the ball more last season and had some success in doing so, while they also play in a hitter-friendly park.

Enter Cesar Hernandez. Hernandez is the same age as Gennett, which perhaps add to the similarities here. But more importantly, Hernandez dropped his GB/FB ratio to 2.14 from 2.48 and 2.65 the two seasons prior. As a result, he hit nine home runs compared to six the year prior and posted his first ISO over .100 in three full seasons. Also working in Hernandez’s favor is the ball park as Philadelphia was the most homer-friendly park to right-handed hitters last season.

To be clear, Hernandez is starting from a different point than Gennett was heading into the 2016 season. But the trend is the same. The difference is that we might be hoping Hernandez goes from nine to 15-plus home runs as opposed to going from 14 to 25-plus. With back-to-back .294 batting average seasons and a double-digit steal season on his record, and with a projected spot at the top of Philly’s lineup, Hernandez has a chance to be a four-category contributor this season if the power comes along.

If you want a guy more analogous to Gennett in that he could go from less than 20 to more than 20 home runs, Tim Anderson fits the bill. Anderson hit 17 home runs last year compared to nine in his rookie season, and his GB/FB ratio dropped from 2.18 to 1.88. It’s possible Anderson continues to make an effort to elevate more and sees his homer total rise well into the twenties. He also has a favorable home park as Chicago was the eighth most hitter-friendly park for right-handed hitters last season.

This Year’s Jimmy Nelson

Jimmy Nelson’s first full season in 2015 was a respectable debut as he posted a 4.11 ERA and 1.29 WHIP. The next year was a big disappointment with a 4.62 ERA and 1.52 WHIP with his strikeout and walk rates falling from around average the year prior to well below average. But then last year Nelson figured it out with a 3.49 ERA that was supported by a 3.42 SIERA. His strikeout rate jumped almost 10 percentage points from the year prior, and he posted his best walk rate of his three full seasons.

It’s a little bit tough to figure out where in the hell Nelson came from last year. He had some prospect-status once upon a time, but he was never a can’t miss prospect who finally delivered on his promise. In fact, one profile of Nelson from back in 2013 compared Nelson to J.J. Hoover, which isn’t exactly a glowing comparison.

Perhaps the one hint in the season prior to Nelson’s breakout about his potential to make a leap was the success he had with his slider. Among qualified pitchers under 30 years old in 2016, Nelson had the seventh best slider per the weighted pitch values over at Fangraphs. The guys above him on that list included Jose Fernandez, Noah Syndergaard and that year’s AL Cy Young winner, Rick Porcello. Those comparisons are a lot better than the Hoover comparison.

Nelson’s slider continued to be an above average pitch for him during his breakout campaign, but it was his curve that really delivered his success. Nelson relied on his fastball less last year in favor of more breaking balls with most of the extra breakers going to his curve, though his slider usage ticked up a bit as well. He used the curve a lot more against lefties and ditched his sinker against lefties in favor of more four-seamers, and he finally tamed hitters who had the platoon advantage as he posted a 3.22 xFIP against lefties last year.

The long story short is that prior to his breakout Nelson already had three pitches he could use and one of them was excellent. That means we’re looking for an under-30 starter who has a couple seasons under his belt but who hasn’t yet broken through and who has at least one stellar pitch.

The guy that fits these criteria may seem a bit too obvious, but Dylan Bundy is like Nelson in a lot of ways. He’s unlike Nelson in that Bundy has way more cache from his time as a prospect, and he’s not quite as old as Nelson. But Bundy has been in the majors for two seasons now, one as a full-time starter, and he has yet to post a sub-4.00 ERA. His strikeout rate has been above average, but with strikeout rates just under 22 percent in the last two years, he hasn’t quite delivered on the promise he had in that department either.

Bundy clearly fits the bill as a guy with a stellar pitch, and he actually has two. Among the qualified, under-30 starters from last season, Bundy had the third best slider and third best changeup per the weighted pitch values on Fangraphs. His slider had the seventh best whiff per swing rate among starters who threw at least 200 sliders last season. There’s no question he has the stuff to take his game to the next level.

While Nelson was going outside the top 400 in ADP last season, Bundy is going just inside the top 200. Bundy’s got name value Nelson never had, so Bundy simply isn’t going to be as cheap. Bundy’s also shown us more than Nelson had prior to last season. But that doesn’t mean Bundy isn’t a value at his current ADP. Nelson was arguably a top 20 fantasy starter last season, and there are still more than 50 other starting pitchers being taken before Bundy. Bundy might not be quite the steal Nelson was, but he still has huge value potential.

This Year’s Luis Severino

Out of all the surprises last year, Severino was one of the biggest. Despite having plenty of prospect status and a couple of decent partial seasons under his belt, Severino was going outside the top 350 in Mock Draft Army ADP last season. He made us all look foolish by posting a sub-3.00 ERA with a 1.04 WHIP and a 29.4 percent strikeout rate. All in all, he was arguably a top 10 fantasy starter.

Because the gap between Severino’s expected value and actual value was so large, it’s tough to identify anyone who could reasonably match Severino’s breakout. It’s not often a guy makes that kind of leap, and it’s even less often that so few people see it coming.

To that end, Jose Berrios is the most obvious candidate to have a Severino-style breakout. Berrios only has about 200 major league innings on his record with a career ERA over 5.00, and his 3.89 ERA last year in his first full season was good but obviously not elite. His age (24), above average strikeout rate last year and his high strikeout rates in the minors are what make him analogous to Severino. The problem is people are expecting a lot more from Berrios than they did of Severino as Berrios’ ADP is just outside the top 100 right now. ADP isn’t everything, and Berrios has a better chance than anyone to be Severino-like, he just won’t return as much value as Severino did if he makes the leap.

Another guy in the Severino mold could have been Archie Bradley had the D’Backs not moved him to the pen last season. It may be that Bradley’s changeup was never going to develop into a reliable third pitch that would allow Bradley to capitalize on his gifts in the starting rotation. But Bradley has the ability to miss bats, and as he’s only now 24, so you wonder if he could have developed as a starter if given the chance. It’s likely moot, but if the D’Backs do ever give him another shot at starting, he’s someone to which you should pay attention.

Finally, German Marquez is a dark horse candidate to have a poor man’s version of a Severino breakout. Marquez doesn’t quite have the velocity that Severino does, but few do, not even Berrios or Bradley. What Marquez does have is some life on his fastball as he was one of seven under-25 starters last year to average 95 mph or more with his fastball.

Marquez has yet to develop his change into a reliable third offering, but if he does, he’ll add it to that lively fastball and a plus curveball. He’s shown good control in 180 big league innings so far, and he missed a decent number of bats last year on his way to a respectable 21 percent strikeout rate.

Of the names floated here as potential Severinos, Marquez is the only one going truly late in drafts with a current NFBC ADP of 336. To be clear, it would be even more shocking if Marquez turns into anything reasonably close to Severino than what Severino did last season. But at his current price, Marquez is the only name mentioned here with as much value potential.