I was reacting to a blend of:
As in... 18-year old in Low-A Anderson Espinoza? Summer of 2017?
Yeah. Yep. Lots of players debut as teenagers, most of them become standouts. For this reason, it's his
stated career goal:
If Espinoza can make it to AA in time to dominate that competition this year, then he can follow in his countryman's footsteps. Not something I'd bet on though. For what it's worth, King Felix has a bigger body type, which may mean nothing in the end but he seemed more physically mature at age 19 than 160-pound Espinoza does.
Whether he can help the Red Sox in 2017 is informed by A) his performance track record so far, B) precedents and what we can learn from them, and C) how he projects qualitatively, on his stuff / approach / endurance / consistency / etc.
To dive deeper into some of the more recent precedents alwyn brought up, let's take some case studies... (
TLDR: Even if he reaches Boston next year, the odds seem strongly against him adding a lot of value to the team in 2017).
Jose Fernandez had an inconsistent first pro season at 18, both K'ing and BB'ing the park in Rookie and A- leagues. In his second season (age 19), he did 14 starts in A (11.3 K9 / 2.1 BB9), then 11 in A+ (9.7 / 2.8). He came up to MLB for his entire 3rd year as a 20yo, pitching 28 starts with a 9.7 K9 / 3.0 BB9. That's sort of an ideal scenario.
Clayton Kershaw wasn't much different. Drafted out of HS, his age 18 year had 10 games in rookie ball (13.1 / 1.2), age 19 was mostly at A ball (20 starts, 12.4 / 4.6) with 5 starts in AA (10.6 / 6.2). His third professional season, 11 more starts in AA saw him put up 8.7 Ks / 2.8 BBs, getting him called up in mid-2008 for half a season. His walk rates stayed high his first few years in the pros (4.3 in 2008, then 4.8 and 3.6 in full seasons) before dropping to 2.1 in his first CYA season in 2011.
Backing down to true teenagers,
MadBum might be the very fastest rise in recent years. He went straight to A-ball at age 18, putting up a 10.4 / 1.3 in 141 IP. In his second season, he got 5 starts in A+ (8.5 / 1.5), 19 in AA (5.8 / 2.5, a sharp drop in K rate), earning a Sept call-up and 10 IP in the majors (10 Ks, 3 BBs). He started his age 20 year in AAA for 14 starts (6.4 / 2.4) before joining the bigs for good for the rest of his 18 starts (7.0 / 2.1). His K rate has been steadily climbing the last 6 years since that drop in AA.
Dylan Bundy might be a cautionary tale. Drafted at 18 at #4 overall, he debuted at 19 in A-ball (8 starts), A+ (12 starts, 10.4 / 2.8) and AA (3 starts), before going up to Baltimore for 2 relief appearances at the end of the year. He spent all of his age 20 year injured, returning at 21 to A- and A+ ball (9 starts total), age 22 in AA (8 starts, plus 2 in the AFL), and began this year at age 23 in the majors as a reliever.
Among foreign signings who remained starters,
Julio Teheran is maybe the best recent example. Spent a short bit of age 17 in rookie ball, but his first full pro season at 18, he had 7 starts in rookie (8.0 / 1.4) and 7 starts in A (6.7 / 2.6). His second full season was very interesting: 7 starts in A (10.3 / 2.3), 10 in A+ (10.8 / 1.8!), 7 in AA (8.6 / 3.8, a slightly worrying shift). In his age 20 year, he began in AAA for 24 starts (7.6 / 3.0), earning a september callup, followed by Dominican winter league. At 21, he put in another 26 starts in AAA (6.7 / 3.0) and a
spot start in the majors, so arguably he was held back a bit by the Braves. His age 22 season, he broke through with a brilliant rookie season for Atlanta (8.2 / 2.2), earning RoY votes.
Roberto Osuna spent a little time in Mexico's leagues as a 16yo, but once joining the pros in the US, his age 17 was abbreviated (43 IP) but promising (10.1 / 3.1 across Rookie / A- ball). He spent all of his 2nd pro year in A ball, only getting 42 IP in 10 starts (injured, I assume) but looking good (10.8 / 2.3). In his 3rd year at age 19, he got 7 decent starts in A+ (12.3 / 3.7), then 6 relief appearances in the AFL (10.9 / 2.9). He went straight from A+/AFL to Toronto the next year at age 20 as a full-time reliever, putting up 9.7 K9 / 2.1 BB9 in 69IP.
A less-recent but meteoric parallel could be
Josh Beckett, who started a little bit older (his first pro season was his age 20 year). He spent that first season dominating A ball (9.3 K/9, 2.3 BB/9), and in his second season, had 12 starts in A+ (13.8 K, 2.1 BB), 13 starts in AA (12.3 K, 2.3 BB), and then 4 september starts in MLB (9.0 K, 4.1 BB). His first two full-time years in the bigs had BB rates in the mid-3s, but his K rates were so high (mid-9s) that he was highly effective - famously so in 2003.
Similarly,
Felix Hernandez
Generally, however, MLB debuts as early as age 20 either are abbreviated september call-ups, go very poorly, or both. Jenrry Mejia got a cup of coffee at 20, had 4 awful starts, and wasn't an effective ML starter until age 23. Arodys Vizcaino did OK in 17 IP of relief at age 20, but then spent 2 years out of baseball and wasn't effective in the bigs until age 24. Jacob Turner had rough 3-start road tests for Detroit at age 20 and 21, before getting traded to Miami and struggling through age 22, and has been bouncing around between the high minors even today at 25. Jordan Lyles stuck at 20, but had 4 terrible seasons in a row before Colorado decided to send him back down, and at 25 still has not been effective in MLB.
By comparison, we thus have
Anderson Espinoza. Last year in 10 starts in rookie ball, he had a 9.0 K9 / 2.0 BB9. In 7 starts thus far at A-ball in Greenville, he's putting up an 11.9 / 3.8. The most successful starters are able to control their walks in A / A+ / AA, so that BB rate is worrying, absent further context.
So he strikes me as being not in the elite group (Fernandez, Beckett, Kershaw) who find effectiveness at the highest level in their 2nd pro year, and add a lot of value to the big team in their 3rd. But may be in the "midlly useful by his 3rd year" category with Osuna, Teheran, and Bumgarner. And that assumes he doesn't end up injured a la Bundy or Vizcaino. I'd be interested to read assessments of his delivery, stuff quality and approach with batters. But from looking at progression and general success at ages across levels in the minors, with an admittedly small sample, I would say counting on him for major value in 2017 is unrealistic.