(Photo by /Icon Sportswire)

Every year there are prospects that stand out in the higher levels of the minor leagues, but very few of them are teenagers. When one of these teenage players performs at a high level, it’s generally considered pretty special. Well, the Blue Jays top prospect and the #3 overall prospect at the beginning of the year according to Baseball America (behind current MLB players Ronald Acuna and Shohei Ohtani), Vladimir Guerrero Jr. has been doing truly special things in AA New Hampshire as a 19-year-old. He’s currently hitting .433/.481/.713 with 10 HRs and 3 SBs in 207 PAs. He’s supported that incredible line with a 9.7% strikeout rate and an 8.7% walk rate which highlights Guerrero Jr.’s combination of strong batting eye and elite contact skills. Overall the season to date has been worth a super impressive 223 wRC+ which leads the Eastern League by a significant margin, and is 2nd best in the entire minor leagues only behind fellow 19-year-old phenom Juan Soto who played about 80% of his games at the A and A+ levels.

There has been only one other player who has posted a better wRC+ (minimum 130 PAs) at AA since Fangraphs has data (2006), his name is Carlos Correa who posted a 226 wRC+ back in 2015 as a 20-year-old while hitting .385/.459/.726 line with 7 HRs in just 133 PAs on his climb to making his major league debut later that year. Note that Guerrero Jr. is achieving this success while being a full year and 11 days younger than the next youngest player in the Eastern League which is his teammate Bo Bichette and that he is 5.3 years younger than the overall league average. This dominance at AA at such a young age led me to wonder if we have ever seen a performance like this before? Let’s find out!

Let’s start by going back as far Fangraphs has data (2006) and look at the best performances of teenage players at the AA level.

Minimum 130 PAs*

There are some very big names on that list, and notably, all have become at least average hitters at the major league level bar Jesus Montero and Jurickson Profar, plus whatever Ronald Acuna turns out to be (tending well). The list is highlighted by a few of baseball’s best hitters including Mike Trout, Manny Machado, and Giancarlo Stanton and yet their numbers at the same age and level are nowhere close to Guerrero Jr.’s. A couple more notable names that didn’t make the list due to performance are Freddie Freeman who posted an 80 wRC+ in 2009, and an 18-year-old Bryce Haper who posted a 100 wRC+ back in 2011.

It is interesting to see that Jason Heyward‘s 2009 season is the closest to Guerrero Jr. numbers wise as he combined the highest walk rate on the list with arguably the best contact skills (Heyward had a 6.8% swinging-strike rate compared to Guerrero Jr.’s current 11%) but slugged over 100 points less (still the 2nd highest mark on the list). Perhaps what Heyward has become today has clouded our memory, but Heyward was an elite prospect who Baseball America ranked #5 overall pre-2009, and #1 overall pre-2010 after his incredible 19-year-old season. Also interesting to note that from this list, Upton, Trout, Profar, and Machado all were called up to the majors from AA and made their MLB debuts in the year listed. Perhaps the same will happen to Guerrero Jr.?

Getting back to the table, it’s clear that Guerrero Jr.’s numbers are in a league of their own by almost every metric, and it’s the elite combination of contact and power that stands out. This clear level above similarly aged players at the same level starts to lend substance to the theory that Guerrero Jr. is perhaps the best and/or most polished teenaged hitter to play at AA ever. Let’s go beyond Fangraphs data and use Baseball Reference as well as the Baseball Cube to go back through history until 1978 (40 years) to see if any more seasons from teenage players stack up:

Minimum 137 PAs*

Name AVG OBP SLG wOBA BB% K% HR SB Delmon Young (2005) .336 .386 .582 .405 6.8 17.8 20 25 Daric Barton (2005) .316 .410 .491 .392 14.1 12.1 5 1 Wilson Betemit (2001) .355 .394 .514 .390 6 18.1 5 6 Adrian Beltre (1998) .321 .411 .581 .421 13.4 12.7 13 20 Andruw Jones (1996) .369 .432 .675 .468 9.7 19.3 12 12 Juan Gonzalez (1989) .293 .342 .506 .376 5.7 17.9 21 1 Gary Sheffield (1988) .314 .386 .591 .426 10.2 12 19 5 Gregg Jefferies (1987) .367 .423 .598 .428 8.6 7.5 20 26 Cal Ripken (1980) .276 .367 .492 .381 12.6 13.3 25 4 Tom Brunansky (1980) .323 .412 .549 .426 13 16.6 24 23

Another interesting mix of names appears here! All of the players on this list had solid MLB careers, some had all-star careers, and there’s even a Hall of Famer on the list, yet none of their teenage seasons at AA matched or have come close to matching what Vladimir Guerrero Jr. is doing this year. I want to point out that there are 4 names that stand out to me on that list when comparing them to Guerrero Jr., Adrian Beltre, Andrew Jones, Gary Sheffield, and Gregg Jefferies and I will talk about them below.

Beltre managed his strikeout to walk ratio pretty similarly to Guerrero Jr. while hitting for lots of contact and power while playing the same position. Beltre was the #3 prospect in baseball according to Baseball America in 1998 and raked his way to the majors after a mid-season call-up from AA. He’s a potential Hall of Fame 3rd baseman with a similar skill set at the plate, yet Guerrero Jr. has been better at the same time in their careers numbers wise.

Andruw Jones has the most comparable batting line to Guerrero Jr. of anyone in the last 40 years, and his wOBA is also the closest at .468. Jones walked slightly more but struck out pretty well twice as often. He made up for a lot of the strikeouts by slugging .675 which is only 38 points behind Guerrero Jr. and the only one within shouting distance. Jones was an elite prospect and may be one of the best prospects of all time with back to back years being ranked #1 prospect in baseball by Baseball America in 1996 and 1997. Even one of the best prospects of all time did not achieve what Guerrero Jr. has to date at the same age and level. Now Jones excelled on the bases and in the field in addition to his gaudy numbers at the plate, and that is part of what made him such a special prospect and what differentiates him from Guerrero Jr. but this is the closest comparable batting line wise and that’s very interesting!

Gary Sheffield similarly to Adrian Beltre above managed his K/BB ratio in a comparable way to Guerrero Jr. while hitting for power (4th highest slugging% after Jones, Heyward, and Jefferies) and average. He both walked and struck out slightly more than Guerrero Jr., yet the ratio is super close. Note that Sheffield may have the most comparable frame on this list at 5 foot 11, 190 lbs compared to Guerrero’s 6 foot 1, 200 lbs. Sheffield made his debut in the majors later that season after a quick 7 game sample at AAA.

The last name that I thought was interesting was Gregg Jefferies, and that’s because he posted the 4th best batting line in the last 40 years for a teenager at AA, and he is also perhaps the closest in terms of walk and strikeout rates. Jefferies walked at pretty much the same rate and struck out slightly less than Guerrero Jr. has to date while hitting for average and power. Where they differentiate is Jeffries was a smaller player with good speed that stole a lot of bases and that’s not a part of Guerrero Jr.’s skillset. He was a huge prospect at the time yet from a batting standpoint, it’s clear that Guerrero Jr. has surpassed what Jefferies accomplished at the same age and level batting wise.

The evidence is clear, the numbers that Vladimir Guerrero Jr. is putting up at AA this year as a 19-year-old is unprecedented, and that makes him perhaps the best and/or most polished teenage hitter to reach the AA level ever. The amazing thing is how big the gap is between Guerrero Jr. and the rest, and that just highlights how special of a talent Guerrero Jr. is at this point. Now development is not linear, and you can see that just because someone is among the best ever at a level of baseball at a particular age does not guarantee greatness (see Jason Heyward). Being at the top of lists like these is encouraging though, and the fact that Guerrero Jr. is a clear level above anything that we have seen before gives hope that he will be able to translate that success to the majors and flourish as a generational type hitter.

Fantasy wise, in dynasty leagues, he’s one of the most valuable assets in fantasy baseball. In redraft leagues, I think he’s worth a pickup in all 12 team leagues and above if you have the room. The fact that other players from those lists above were called up from AA to the majors with lesser numbers proves that Guerrero Jr. is likely ready for a new challenge and I think if he receives the call to the majors, he could be an asset down the stretch for your fantasy teams. Even Steamer projections who are notoriously conservative project Guerrero Jr. for a .296/.358/.471 batting line for the rest of the season at the major league level with an 8.2% BB rate and a 14.6% K rate that would be worth a 119 wRC+. For reference, Khris Davis of the Oakland Athletics is currently posting a 119 wRC+, and names like Eric Hosmer and Giancarlo Stanton as well as Rhys Hoskins all have performed below a 119 wRC+ to date. I have no idea when the Blue Jays will call up Guerreo Jr., but I would hate to miss out on a talent like this. Again, no teenage hitter has ever been as dominant as he has at the AA level, this is a potential generational type hitter!