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:

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.


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:

Buxton v. Mondesi: AAA Stats
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).


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):

Buxton v. Mondesi: Plate Discipline
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.

Currently investigating the relationship between pitcher effectiveness and beard density. Two-time FSWA award winner, including 2018 Baseball Writer of the Year, and 8-time award finalist. Featured in Lindy's magazine (2018, 2019), Rotowire magazine (2021), and Baseball Prospectus (2022). Tout Wars competitor. Biased toward a nicely rolled baseball pant.

Newest Most Voted
Inline Feedbacks
View all comments
jim fetterolf
4 years ago

Might be useful to look at the trends for these young players.