Adalberto Mondesi, and the Byron Buxton Question(s)
I think there are not one, but many, questions because there are not one, but many, ways Adalberto Mondesi and Byron Buxton are similar.
Here’s one answer to one possible question:
who has the best fantasy season in 2019?
— Alex "Oxlade" Chamberlain (@DolphHauldhagen) August 29, 2018
I can’t say I’m surprised, but I’m kind of surprised. I asked this question very deliberately, its design not remotely accidental, the response options dripping with subtext. Mondesi, with his elite speed, decent power for a speedster, and very questionable contact skills, in 2018 is almost a dead ringer for Buxton in 2017. Mondesi doesn’t quite have Buxton’s baggage — he doesn’t carry the weight of expectations of a No. 1 prospect — but he has his own, continuing a familial legacy. But they do have a lot in common, as aforementioned, which can be summarily boiled down to this great quip from our Eric Longenhagen: “wholly untamed physical abilities.”
Billy Hamilton, I’ve included for scale. Should Hamilton have sustained his typical rate of stolen bases, he’d represent a hypothetical Mondesi outcome over a full season: half a dozen home runs, 60 stolen bases, and a pitiful batting average (or on-base percentage — take your pick). Unfortunately, Hamilton’s pace has severely slowed, making him a seemingly obvious fade next year. But it’s important to note: Hamilton has guaranteed playing time, even if he doesn’t necessarily deserve it. It’s a luxury Buxton and Mondesi cannot currently claim for themselves. (Also, I didn’t want you to simply fade Buxton because of his tremendously unprofitable 2018 season.)
Let’s compare Buxton, Mondesi, and Hamilton on the basis of three traditional categories: power, speed, and batting average.
Power
Hamilton is the clear loser here. As noted, he resembles a full-season version of Mondesi devoid of power. But Buxton and Mondesi are really similar. Through 605 career plate appearances, Buxton has hit 16 home runs and recorded a .141 isolated power (ISO); Mondesi, through 236 PA, has 7 home runs (which prorates to 18 home runs over 605 PA) and a .153 ISO. We can’t reliably project Mondesi’s power with 40% of one Major League season, but it’s evident the two can be reasonably compared in this regard. If we’re looking for an edge — if it’s necessary to pick a “winner” here — then Minor League numbers could help us further delineate the two. Buxton’s and Mondesi’s career numbers at Triple-A:
| Name | G | AB | PA | HR | BB | SO | SB | AVG | OBP | SLG | ISO |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Buxton | 93 | 361 | 395 | 18 | 28 | 107 | 13 | 0.307 | 0.362 | 0.537 | 0.230 |
| Mondesi | 166 | 650 | 721 | 25 | 43 | 176 | 55 | 0.283 | 0.326 | 0.508 | 0.225 |
Between AAA and the majors, Mondesi and Buxton are dead ringers for each other in terms of power. It’s not helpful, at least not for the purpose of picking one over the other, but it does help to solidify the idea that both carry 15-homer (and upwards of 20-homer) power. It makes it a bit easier to see why fantasy owners adored Buxton through rose-colored lenses in drafts last year (he was a top-50 draft pick last year in the National Fantasy Baseball Championship).
Speed
Let’s make one thing clear: frequency does not necessarily indicate skill. With a 90% success rate on the basepaths at the Major League level, it’s clear Buxton is a skilled baserunner. But he has failed to steal commensurate with his Minor League rate of attempts, making him (in the current high-power, low-speed fantasy context) an elite, but not game-changing, provider of stolen bases. It doesn’t make him unskilled, just inopportune. He’s an alleged 70-grade runner, and that shows in his baserunning and fielding efficiency, but it unfortunately has not manifested in Hamiltonian, or even Trea Turnerian, stolen base totals.
Whereas Buxton has stolen about 26 bases per 600 PA in the majors (and, at Triple-A, a 20-steal pace), Mondesi sports a 50-steal pace during his brief Major League career (including a 60-plus pace in 2018) supported by a 51-steal pace at Triple-A. Mondesi has presented himself as twice the baserunning threat than Buxton for fantasy purposes, utterly tipping the scales in his favor.
Batting Average (aka Contact and Plate Discipline)
This comparison gets a little dicier. One of my favorite standalone metrics for judging contact skills and plate discipline is swinging strike rate (SwStr%). Buxton’s career 14.1% whiff rate paints him has an atrociously bad bat, especially considering his calling-card skill is speed, but it looks heaven-sent compared to Mondesi’s catastrophic 18.2% career rate. We saw how this hyper-volatile skill set derailed the sequel to Buxton’s breakout: through 94 plate appearances, he struck out nearly 30% of the time, hit nary a home run, and recorded a whopping -3 wRC+. If Buxton’s lack of contact skills “predicted” his implosion (spoiler: they did), it’s hard not to think the same could happen to Mondesi — more readily, even, given the depths of his contact-oriented deficit relative to Buxton.
This argument deserves more nuance, though, because while Mondesi swings and misses more often, he also simply swings more often, which changes the dynamic of how whiff rates are interpreted. Consider Buxton and Mondesi alongside Javier Baez, 2018’s finest breakout (“full” breakout, for those who want to argue he began to break out in 2017, which is more than fair):
| Name | O-Swing% | Z-Swing% | Swing% | O-Contact% | Z-Contact% | Contact% | SwStr% |
|---|---|---|---|---|---|---|---|
| Buxton | 32.50% | 67.80% | 49.10% | 52.60% | 82.20% | 71.90% | 13.80% |
| Mondesi | 38.00% | 77.70% | 55.20% | 45.10% | 80.40% | 66.60% | 18.40% |
| Baez | 46.40% | 76.20% | 58.00% | 55.30% | 80.30% | 68.00% | 18.50% |
Baez’s whiff rate is terrifying. I used to think if you’re going to swing and miss more than, like, 13% of the time, you better hit for a ton of power. Turns out, if you swing and miss and also just swing at everything, you actually reduce your probability of a strikeout. It makes sense, too: Baez would be a disaster if, instead of swinging 58% of the time, he swung half as often. He’d take more pitches, some of which would be balls but many more of which would be strikes. His swings would carry an inherently low probability of contact, making the likelihood of a ball in play pretty slim. His tendency to swing often, despite those swings often failing to make contact, reduces the number of deep counts Baez sees. This shows up in his plate discipline metrics: he still strikes out a ton, and he hardly walks. He effectively ensures his plate appearances ends on his terms — even the strikeouts, of which 86% end in a swing, 26th-most among 156 qualified hitters.
Mondesi resembles the high-strikeout, low-walk hitters of the league: Baez, Salvador Perez, Adam Jones, Eddie Rosario, Tim Anderson, Jonathan Schoop, and more. All are acceptable hitters — much more acceptable for fantasy than real-life purposes — who, except for Jones, have seen their share of struggles at one point or another. Mondesi will likely fit this mold, and his owners (and the Royals) will need to learn patience. Mondesi might further distinguish himself from Buxton, though: while he swings (and misses) more often on pitches outside the zone, resulting in a lower overall contact rate (Contact%), he swings much more often at pitches in the zone (Z-Swing%). It’s open to interpretation, but it seems to me Mondesi, while perhaps lacking by way of plate discipline, at least has a more efficacious approach, taking hacks at the pitches that don’t matter but also the ones that do. For a very weak hit tool, it would serve Buxton well to be more aggressive, especially on pitches in the zone.
All of this is to say I think Mondesi gets the edge here, but it doesn’t mean he’s out of the woods. While he has pushed his strikeout rate (K%) below 30%, it doesn’t guarantee it’ll stay there — to attest, it floated well above 30% in comparably small samples in 2016 and 2017. The big difference: Mondesi’s rate of in-zone swings, which is up anywhere from 10 to 12 percentage points, depending on your source. Over a full season, his current 80.4% rate would pace the league if it weren’t for the delightful Freddie Freeman.
I think the big question, then, is Mondesi’s ability to repeat this aggression. If he can do it, it could keep him afloat. If he can’t, it could sink him as quickly as Buxton was sunk this year.
What about 2019?
Let’s start with Buxton. I say this without exaggeration: he was the easiest fade for me last year, (I documented some thoughts on his volatility here), and he busted monumentally. Alas, Buxton will not be a top-50 pick in 2018. He probably won’t be a top-100 pick or even a top-150 pick. His stock has taken a colossal, but completely warranted, hit, and he’ll come at a steep discount in 2019, in relative terms.
If it weren’t for Buxton, we might not even have a frame of reference in which to reasonably evaluate Mondesi. Fact of the matter is Mondesi looks a lot like Buxton in almost every facet of the (fantasy) game and therefore carries similarly high risk of busting. Mondesi probably won’t be a top-50 pick; he doesn’t carry the (dare I say toxic?) top-prospect hype that Buxton did, which could give him extra cushion on draft day next year. His apparent propensity to steal more often than Buxton further elevates his floor, too. That’s where the Hamilton comparison comes into play: Hamilton is all but useless outside of game-changing speed, yet he’s worth rostering. It might surprise you, but even with a meager (for him) 35-steal pace, Billy Hams is a top-150 player per ESPN’s Player Rater. I bet you he’ll be cheaper than that next year, priming him to turn an easy profit.
But I digress. Mondesi, like Hamilton, has similarly game-changing speed and could readily be a black hole at batting average. But if he’s a full-time player (assuming Alcides Escobar has been shown the door, oh, please, please), Mondesi would be a must-own player simply on the basis of his speed, in spite of the damage he’d inflict to all your other categories except power.
Mondesi carries unique potential to be a 15-homer, 40-steal hitter with room for more. He potentially has Hamilton’s speed, Buxton’s power, and neither’s prospect pedigree, putting him in an uncharted valuation situation entering 2019. He’s essentially a generic-brand low-average version of Turner or Starling Marte. Reframing his value, his better-case scenario might be, well, a carbon copy of 2017 Buxton, but with more steals and less batting average. That’s a top-120 player, but one who comes with an exceeding amount of risk. It’s simply too early to give you a clear-cut answer for his prospects heading into 2019. For now, just enjoy the ride.
Two-time FSWA award winner, including 2018 Baseball Writer of the Year, and 8-time award finalist. Featured in the print edition of Baseball Prospectus since 2022 (2026 edition out now). Biased toward a nicely rolled baseball pant.
Might be useful to look at the trends for these young players.
Great writeup–Mondesi’s upside had gone too far under the radar before now. Note Jon Villar is also a very good comp for Mondesi — 15 homers 30+ sbs (projected this year, and a typical pace for him), and similar discipline issues. Villar’s batting average is also an issue besides his crazy 2016 with 19 homers and 60 sbs (about mondesi’s currnent pace). That year his babip was 370 and he batted 285.
Great comp! Probably the best comp of all, honestly. Jealous I didn’t think of it myself. Same upside with all the same problems. Breaks right, and he’s potentially an elite fantasy asset, but it’s evident these things rarely break right (or stick when they do).
Thanks 🙂 you’re not the only one who spent the day searching for mondesi comps haha (I found a lot of the same ones perusing the preseason auction calc projections…plus Villar and sorta zimmer)…and yeah, agreed, crazy to think Villar was a second round pick going into 2017.
Hamilton is on pace for a 2 WAR year. Not great, but not sure why he wouldn’t deserve his playing time.
Should have clarified: plate appearances. That value is all tied up in his defense and baserunning, not his bat.
You should have tossed Moncada in here. Spitting image of Buxton’s minor league numbers and discipline issues and if he puts up a good September he will be similarly overvalued
Moncada has always walked quite a bit more than Buxton ever did, though.
Mondesi was brought up so early that he got to the 130 plate appearances that disqualify you from rookie/prospect status at age 20, well before he was really ready for the major leagues, and fell out of the prospect limelight. Had that not happened, he might well have had the weight of high prospect rankings and expectations hanging around his neck just like Buxton.
It is easy to forget that Mondesi only turned 23 just a little over a month ago. His BB/K ratio is not awful because of the K% part, which has basically been improving as he ages – last year and this year at AAA (where he has had the bulk of his ABs), his K% was 24.1% and 22.6%. While nothing to write home about, that is not really terrible at all for a 20 and 21 year old player at the AAA level, especially since he has shown some improvement. The bigger issue is the BB% part, which has hovered in the 5-6% range ever since rookie ball. If he could improve on that front, he could turn himself into a very valuable player. but that is easier said than done.
Mondesi might be worth the risk at SS but he first has to beat out Nicky Lopez for the job next spring. The Royals choice is Modesi’s speed vs Lopez’ .364 OBP at AAA with only 29Ks in 250 PAs. The Royals could move Mondesi to CF but he’d be worth less there.