How Big Is Too Big for Shortstop? by Eric Longenhagen September 20, 2017 When examining the 2018 draft’s collection of top high-school shortstops, one is confronted with three vastly different physical entities in Santiago HS (CA) SS Brice Turang, Montverde Academy (FL) SS Nader De Sedas, and North Broward Prep (FL) infielder Xavier Edwards. Edwards is explosive. A plus-plus runner with good hands and enough arm for the left side of the infield, he also possesses gap-to-gap power. He’s performed, in games, against elite pitching and might be my first pick among all 2018 high schoolers if we were picking teams for a game of sandlot ball tomorrow. He’s also a slight 5-foot-9 and 155 pounds. De Sedas is a switch-hitting hammer who was being covered in his native Panama when he was just 13 years old. He moved to Florida late in adolescence and has shown big raw power from both sides of the plate, as well as feel to hit in games despite having adopted switch-hitting somewhat recently. But while De Sedas has premium arm strength and is smooth for his size, he’s also rather big. At a listed 6-foot-2, 192 pounds, De Sedas is already larger than Manny Machado (6-foot-3, 185) and Evan Longoria (6-foot-2, 170) were when coming out of high school. Finally, there’s Turang. Lean, rangy, and acrobatic, he also features a plus arm. He’s instinctive, procedurally advanced, and a potential plus defender at short, but he may have limited, one-dimensional offensive impact. As with any prospect, I’ve attempted to project the future defensive value of the three players mentioned here. Because of their vastly different builds, however, I became curious about the physical makeup of major-league baseball’s current shortstops and how the upcoming draft class — especially De Sedas, who belongs near the top of the class if he can stay at short — fits among them. To address my curiosity, I began compiling not only the current heights and weights of the league’s shortstops but also their heights and weights at age 17 — or, roughly the age at which each of them was either drafted or signed out of Latin America. I then expanded my criteria to include all players who had recorded at least 450 innings at shortstop during the last three seasons. I also calculated both current BMI and also BMI at age 17 — as well as changes in height, weight, and BMI during that span. There are some issues with this data. For one, it assumes that MLB teams are forthright about their players’ heights and weights, which is unlikely and, at times, demonstrably false. There was also no single source from which to obtain heights and weights for these players when they were 17. Where possible, I used draft data from MLB.com’s Draft Tracker, but I also dove into past Baseball America Prospect Handbooks, old AZL and GCL rosters, and even some local newspaper articles. (For instance, nothing was written about Wilmer Difo as an amateur and it took a 2014 James Wagner Washington Post article for me to find any record of his teenage weight.) It was especially hard to find weights for Cuban players like Alexei Ramirez, as many of those players didn’t join MLB clubs until their mid-20s. If I couldn’t find old Cuban National Team rosters with the measurements of a given player at age 17, I got as close as I could. Alexei’s initial weight was measured at age 20, the furthest from 17 of any player on the list. The entire table of data is located at the bottom of the article. Heights, which rarely changed from age 17 to present, are listed in inches. Here are the averages for current big-league shortstops. MLB Shortstop Average Height Wt BMI Age-17 Height Age-17 Weight Age-17 BMI Weight Change BMI Change Average 72 196 26 72 171 23 28 3 Shortstop requires terrific lateral range. Modern defensive positioning might hide some deficiencies in this area — and this one specific skill has probably become less important than it once was — but it’s still a requirement. Statcast’s Sprint Speed Leaderboard, for example, indicates that shortstops run better than most other big leaguers, supporting the notion that players must exhibit a baseline level of athleticism for the position. It’s intuitive that, as players get bigger and heavier, they become slower — and also less likely to remain at shortstop, where lateral quickness matters. I’m actually unable to find any statistical evidence that illustrates the effect of size on defensive performance — not within this sample of shortstops, at least. It’s quite possibly a product of the large sample sizes required for defensive metrics to become reliable, but I found no strong correlation between weight or BMI and any of Defensive Runs Saved, Range Runs, or Defensive Runs Above Average. But I think we can look at the shape of the data and see where the upper bound of physical viability lies. Corey Seager and Carlos Correa are our two tallest shortstops, responsible for the right-most bar on this histogram: Meanwhile, here are the weights of all current shortstops: And the BMIs: The larger BMI figures actually do seem to correlate with a drop-off in defensive performance. Many players with a BMI of 28 or more in our sample have either already moved off of shortstop, are late-career stopgaps, or have clear defensive warts to the naked eye. Shortstops with BMI of 28 or Greater Name Ht Wt BMI Age-17 Height Age-17 Wt Age-17 BMI DRS DEF BMI Delta Sprint Weight Delta Acq Eugenio Suarez 71 213 30 71 155 22 -12 -8.0 8 26.7 58 Int’l Starlin Castro 74 230 30 73 160 21 -4 6.2 8 27 70 Int’l Jean Segura 70 205 29 71 155 22 -6 6.0 7.8 27.3 50 Int’l Jhonny Peralta 74 225 29 72 185 25 -8 -1.5 4 27 40 Int’l Jonathan Villar 73 215 28 73 180 24 6 -8.0 5 27.5 35 Int’l Erick Aybar 70 195 28 70 160 23 -10 -4.0 5.0 27.4 35 Int’l Wilmer Difo 71 200 28 70 160 23 14 7.1 4.9 29 40 Int’l D. Robertson 71 200 28 72 190 26 2 2.1 27.2 10 Draft Ruben Tejada 71 200 28 71 162 23 2 -1.8 5.3 27 38 Int’l Pat Valaika 71 200 28 71 170 24 -2 4.2 27.5 30 Draft Jorge Polanco 71 200 28 71 165 23 -9 -7.4 4.9 28.2 35 Int’l D. Espinosa 72 205 28 71 165 23 5 6.4 5 27.1 40 Draft A. Cabrera 72 205 28 72 185 25 -24 -1.0 2.7 25.7 20 Int’l Trevor Story 73 210 28 72 175 24 13 7.2 4.0 28.4 35 Draft X. Bogaerts 73 210 28 73 185 24 -23 16.7 3.3 28.2 25 Int’l Zack Cozart 72 204 28 73 180 24 18 27.0 3.9 26.6 24 Draft B. Crawford 74 215 28 73 180 24 46 57.6 3.9 26.4 35 Draft Brad Miller 74 215 28 73 175 23 -18 -3.3 5 27.6 40 Draft By stacking some histograms, it’s possible to see how the weight and BMI of shortstops changes from their earliest days as a prospect to physical maturity. First, with weight: And then BMI: As I collected the data, it looked as though there were some differences between the way domestic and international amateurs had developed. Here are the results when I split the two groups: MLB Shortstop Averages Ht Wt BMI Age-17 Height Age-17 Weight 17BMI Weight Change BMI Change Averages 72 196 26 72 171 23 28 3 Averages (Latin America) 72 193 26 72 164 23 28 4 Averages (Domestic) 73 198 26 72 177 24 22 3 On average, Latin American shortstop prospects acquire more mass between age 17 and maturity. Socioeconomic factors are likely responsible for that. Because it’s my desire, however, to project domestic, draft-eligible amateurs, I’ll be using the data from that subgroup of current MLB shortstop as my main resource. There was no correlation between height and weight change within shortstop, so I’ve blanketed the average across all of the 2018 draft class. The names you see below are all 2018 draft-eligible high schoolers whom I’ve seen play shortstop. They’re sorted by projected weight (Prj Weight). 2018 Draft High School Shortstops Name Prj Ht Prj Weight Prj BMI Ht Wt BMI Cam McMillan 77 227 27 77 205 24 Seth Halvorsen 73 220 29 73 198 26 Jordan Groshans 75 217 27 75 195 24 Nander De Sedas 74 214 27 74 192 25 Vinny Tosti 72 212 29 72 190 26 Osiris Johnson 73 209 28 73 187 25 Kendall Simmons 74 207 27 74 185 24 John Rodriguez 74 207 27 74 185 24 Bryce Reagen 73 207 27 73 185 24 Kevin Vargas 75 205 26 75 183 23 Timmy Borden 74 202 26 74 180 23 Jake Dukart 74 202 26 74 180 23 Raynel Delgado 73 202 27 73 180 24 Mateo Gil 73 202 27 73 180 24 Kody Darcy 74 197 25 74 175 22 Brandon Dieter 73 197 26 73 175 23 Emilio Rosas 73 197 26 73 175 23 Jeremiah Jackson 71 197 27 71 175 24 Brice Turang 73 192 25 73 170 22 Blaze Alexander 71 192 27 71 170 24 Jonathan Ornelas 72 177 24 72 155 21 Xavier Edwards 69 177 26 69 155 23 The bottom four names on the table are all players whom I’d already projected at shortstop based solely on my in-person evaluations from this summer. You can see De Sedas’ projected weight is right on the fringe of what we currently see at shortstop. Nine current/recent MLB shortstops weigh 215 pounds or more and most of them aren’t currently good defenders there. Corey Seager and Carlos Correa, each very rare talents, feature two of the better gloves in that group. Shortstops can compensate for a lack of range with other attributes (Correa, for example, features excellent arm strength) and it’s possible that De Sedas can do this (he has at least a 60 arm). I think his bat is impressive enough that he’ll garner top-10 consideration in next year’s draft even if he’s evaluated as a third baseman. But for now I think there’s reason to be apprehensive about projecting him as a shortstop. Turang, meanwhile, falls smack into the middle of the group, further supporting the notion that he’s a near lock to stay at short. I also ran projections for prospects in pro ball based on their age-17 weight. The following table includes prospects who have garnered recent consideration at shortstop. Their projected weights are based on their weight at age 17. I’ve also included their means of acquisition in each case. Only Willy Adames has outgrown projection in a meaningful way. Pro Shortstop Prospects Name Ht Wt BMI Age-17 Height Age-17 Weight Age-17 BMI Acq Prj Weight Prj BMI Bo Bichette 72 200 27 71 201 28 Draft 223 31 Hunter Greene 76 197 24 76 197 24 Draft 219 27 Kevin Maitan 74 190 24 74 190 24 Int’l 218 27 Joe Dunand 74 205 26 75 190 24 Draft 212 27 Carter Kieboom 74 190 24 74 190 24 Draft 212 27 Jean Carmona 73 183 24 73 183 24 Int’l 211 27 Royce Lewis 74 188 24 74 188 24 Draft 210 27 Freudis Nova 73 180 24 73 180 24 Int’l 208 27 Cole Tucker 75 185 23 75 185 23 Draft 207 26 Fernando Tatis, Jr. 75 185 23 73 175 23 Int’l 203 26 Isaac Paredes 71 175 24 71 175 24 Int’l 203 27 Franklin Barreto 70 190 27 69 175 26 Int’l 203 29 J.P. Crawford 74 180 23 74 180 23 Draft 202 26 Kevin Newman 73 180 24 73 180 24 Draft 202 27 Brendan Rodgers 72 180 24 72 180 24 Draft 202 27 Logan Warmoth 72 190 26 72 180 24 Draft 202 27 Lucius Fox 74 175 22 74 170 22 Int’l 198 25 Wander Franco 70 170 24 70 170 24 Int’l 198 27 Chris Seise 74 175 22 74 175 22 Draft 197 25 Nick Gordon 72 160 22 74 175 22 Draft 197 25 Ronny Mauricio 75 166 21 75 166 21 Int’l 194 24 Wander Javier 73 165 22 73 165 22 Int’l 193 25 Andres Gimenez 71 176 25 71 165 23 Int’l 193 26 Gavin Lux 74 190 24 74 170 22 Draft 192 25 Gleyber Torres 73 175 23 71 160 22 Int’l 188 25 Raul A. Mondesi 73 185 24 71 160 22 Int’l 188 25 Willy Adames 72 200 27 71 160 22 Int’l 188 25 Aramis Ademan 71 160 22 71 160 22 Int’l 188 25 Delvin Perez 75 175 22 75 165 21 Draft 187 24 Jurickson Profar 72 190 26 71 165 23 Int’l 187 26 Willi Castro 73 165 22 72 150 20 Int’l 178 23 Jazz Chisholm 71 165 23 69 150 22 Int’l 178 25 Nick Allen 69 155 23 69 155 23 Draft 177 26 Nicky Lopez 71 175 24 70 150 22 Draft 172 25 And here’s the full table of data I compiled for major leaguers. MLB Shortstops Name Ht Wt BMI Age-17 Height Age-17 Weight Age-17 BMI BMI Change Sprint Weight Change Acq Corey Seager 76 220 27 76 205 25 1.8 27.2 15 Draft Carlos Correa 76 215 26 76 190 23 3.0 27.9 25 Draft Ian Desmond 75 215 27 74 185 24 3 27.5 30 Draft Jordy Mercer 75 210 26 75 175 22 4.4 27.5 35 Draft Didi Gregorious 75 205 26 73 152 20 5.6 28.3 53 Int’l Troy Tulowitzki 75 205 26 74 170 22 3.8 25.2 35 Draft Wilmer Flores 75 205 26 75 175 22 4 25.7 30 Int’l Starlin Castro 74 230 30 73 160 21 8 27 70 Int’l Jhonny Peralta 74 225 29 72 185 25 4 27 40 Int’l Brad Miller 74 215 28 73 175 23 5 27.6 40 Draft Brandon Crawford 74 215 28 73 180 24 3.9 26.4 35 Draft Adam Rosales 74 205 26 74 195 25 1.3 27.2 10 Draft Andrelton Simmons 74 200 26 74 170 22 3.9 27.8 30 Draft Chad Pinder 74 195 25 72 170 23 2.0 27.4 25 Draft Nick Ahmed 74 195 25 72 180 24 0.6 28.1 15 Draft Amed Rosario 74 190 24 74 175 22 1.9 29.7 15 Int’l Alexei Ramirez 74 180 23 73 170 22 1 27 10 Int’l Jonathan Villar 73 215 28 73 180 24 5 27.5 35 Int’l Trevor Story 73 210 28 72 175 24 4.0 28.4 35 Draft Xander Bogaerts 73 210 28 73 185 24 3.3 28.2 25 Int’l Marwin Gonzalez 73 205 27 73 186 25 3 26.5 19 Int’l Tim Beckham 73 205 27 72 188 25 1.5 27.6 17 Draft J.J. Hardy 73 200 26 73 170 22 4.0 26.2 30 Draft Clint Barmes 73 200 26 73 190 25 1 27 10 Draft Paul DeJong 73 195 26 73 180 24 2.0 27.8 15 Draft Aledmys Diaz 73 195 26 72 183 25 1 27.9 12 Int’l Dansby Swanson 73 190 25 72 170 23 2.0 28.4 20 Draft Alcides Escobar 73 185 24 73 155 20 4.0 28.2 30 Int’l Trea Turner 73 185 24 74 160 21 3.9 29.2 25 Draft Tim Anderson 73 185 24 72 165 22 2.0 28.6 20 Draft Ketel Marte 73 180 24 73 155 20 3.3 28.6 25 Int’l J.T. Riddle 73 180 24 75 175 22 1.9 28 5 Draft Dixon Machado 73 170 22 72 140 19 3.4 27.1 30 Int’l Luis Sardinas 73 160 21 73 150 20 1 28 10 Int’l D. Espinosa 72 205 28 71 165 23 5 27.1 40 Draft Asdrubal Cabrera 72 205 28 72 185 25 2.7 25.7 20 Int’l Zack Cozart 72 204 28 73 180 24 3.9 26.6 24 Draft Stephen Drew 72 200 27 72 170 23 4.1 25.9 30 Draft Elvis Andrus 72 200 27 72 185 25 2.0 27.5 15 Int’l Addison Russell 72 200 27 72 215 29 -2.0 27.7 -15 Draft Jose Peraza 72 196 27 72 165 22 4.2 28.1 31 Int’l Eduardo Nunez 72 195 26 72 155 21 5 27.8 40 Int’l Jose Reyes 72 195 26 72 160 22 4.7 27.8 35 Int’l Marcus Semien 72 195 26 72 170 23 3.4 28 25 Draft A. Hechavarria 72 195 26 71 178 25 1.6 27.5 17 Int’l Javier Baez 72 190 26 72 180 24 1.4 28.3 10 Draft Orlando Arcia 72 165 22 72 165 22 0.0 27.4 0 Int’l Eugenio Suarez 71 213 30 71 155 22 8 26.7 58 Int’l Ruben Tejada 71 200 28 71 162 23 5.3 27 38 Int’l Wilmer Difo 71 200 28 70 160 23 4.9 29 40 Int’l Jorge Polanco 71 200 28 71 165 23 4.9 28.2 35 Int’l Ruben Tejada 71 200 28 71 165 23 5 27 35 Int’l Pat Valaika 71 200 28 71 170 24 4.2 27.5 30 Draft D. Robertson 71 200 28 72 190 26 2.1 27.2 10 Draft Miguel Rojas 71 195 27 69 175 26 1.4 27.3 20 Int’l Francisco Lindor 71 190 26 71 175 24 2.1 28.1 15 Draft Danny Santana 71 185 26 71 150 21 5 28.8 35 Int’l Jose Iglesias 71 185 26 71 175 24 1.4 28.2 10 Int’l Jean Segura 70 205 29 71 155 22 7.8 27.3 50 Int’l Erick Aybar 70 195 28 70 160 23 5.0 27.4 35 Int’l Daniel Descalso 70 190 27 70 180 26 1 26.9 10 Draft Eduardo Escobar 70 185 27 70 150 22 5.0 28.1 35 Int’l Freddy Galvis 70 185 27 70 154 22 4.4 27.4 31 Int’l Chris Owings 70 185 27 71 175 24 2.1 27.8 10 Draft Ryan Goins 70 180 26 69 155 23 2.9 26.9 25 Draft Jimmy Rollins 67 175 27 67 154 24 3 28 21 Draft Ronald Torreyes 67 151 24 67 140 22 1.7 27.9 11 Int’l Alexi Amarista 66 160 26 68 150 23 3 27.4 10 Int’l