This week will be the last of two things for Chicago Cubs outfield prospect Nelson Velazquez: his last week in a dominant Arizona Fall League season, and his last week not on the Cubs 40-man roster. The likely-MVP season he’s having in Mesa concludes this weekend, and as we’ve said many times over the last month, he’s certainly succeeded in what he set out to accomplish: he’s earned that roster spot.
While Nelson’s months-long hot streak actually dates back to before his time in the AFL, I think it’s fair to ask how much weight these 25-or-so AFL games should have on our expectations for Velazquez moving forward. What does a dominant AFL season MEAN for a prospect’s likelihood of future success?
Nelson Velazquez CRUSHES one to left!
— MLB's Arizona Fall League (@MLBazFallLeague) November 7, 2021
For example way of looking at things, with a decent week, Velazquez should end up with the league lead in OPS. Here are the players that have held that title in the league since 2005: Eric Duncan, Chip Cannon, Sam Fuld, Jason Donald, Colin Curtis, Dustin Ackley, Mike Olt, Josh Prince, Kris Bryant, Greg Bird, Adam Engel, Bradley Zimmer, Eric Filia, Will Craig, and Greg Deichmann.
Despite some “fun” Cubs connections on there, and with the exception of one Kristopher Lee Bryant, that’s a pretty underwhelming collection of names, right? But it’s also a tiny sample with some narrow criteria. I think back to this Eno Sarris FanGraphs piece from 2013, which found that position players selected to play in the Rising Stars game had as much chance of Major League success as a top 50 Baseball America prospect (about 31% at the time).
I decided to use Eno’s piece as a jumping off point, and looked back on all AFL hitters from 2006-2017 who finished the season with a .900 OPS or greater (minimum 60 PA). It’s worth saying up front that the AFL has had some significant variance in their run-scoring environments during those 12 years, so a static OPS number is probably flawed, but it’s all I had, and it’s better than nothing. It also leads us to a larger sample than in the 2013 FanGraphs study, with 160 players meeting the criteria.
If we define “Major League success” in the same way that Sarris did – 1.5 fWAR per 600 plate appearances (a playable big leaguer) – we have 48 players (30%) that reach the threshold, that same mark carried by top 50 prospects. Players that exceed a 1.000 OPS season, which Velazquez almost surely will, succeeded in 25 of 70 occasions, a rate of 35.7%. This is in the range of the rate of success for top 30 BA prospects, per this (admittedly older) piece at Royals Review.
In other words, you *COULD* use this data, and Velazquez’s performance this fall, to infer that he has approximately the same chance of future big league success as a top 30-50 prospect in baseball. I know. That’s kinda shocking.
I’m admittedly a little dubious of these numbers, doubtful that 60-120 PA can have meaningful predicting power for offensive prospects. So your response is probably similar to mine, and I’d caution you against suddenly thinking of Velazquez *AS* a top 30-50 prospect in the game. We can’t and shouldn’t say that. But we should keep in mind that it’s also not just a sample of games that brings a guy into this conversation, because there is also the predicate of being a good enough player to have been selected to play in the league in the first place (and, further, in the Rising Stars Game).
Also, keep in mind that the measure of “Major League success” here is pretty modest. We’re not talking about the chances – still well below 50%! – that a guy like Velazquez becomes a star. We’re just talking about the chances he becomes a playable big leaguer. You have to keep the context in mind.
Ultimately, like so much in prospecting, you review the data, sure, but it’s at least as much about what our eyes are telling us.
A lot has changed. Nelson’s obvious increased muscle mass allows for less load to create equal/more power. Contact point up. Flatter bat path. pic.twitter.com/GsZswpe6Lt
— Cubs Prospects – Bryan Smith (@cubprospects) November 3, 2021
When it comes to Nelson Velazquez, our eyes are showing someone whose swing has really evolved, utilizing his strength and bat speed to simplify (I’d point you to Greg Zumach’s post on those swing changes). A contact point more out in front of him leads to easy and sustainable plus power, but a flatter bat path is also going to come with inevitable swings and misses. I did appreciate that Trevor Hooth noticed Velazquez’ increased habit of lengthening at-bats at the season went along, as that’s jumped out to me recently as well. If those eventually translate into fewer strikeouts, which would require another adjustment (in a career full of them), that’s where Velazquez’s odds of Major League success rise the most.
The odds seem to be tilting more and more each week toward future big league success for Velazquez, but hopefully we’ve shed some light on what those odds might realistically be versus what they feel like in the midst of this hot streak.
Meanwhile, when the Rule 5 Draft rostering deadline arrives in just a few days, Velazquez will find himself added to the Cubs’ 40-man roster, and his progression toward finding that big league success, if it comes, will have cleared another hurdle.
Nelson Velazquez’s 6th @MLBazFallLeague HR.
105 mph off the bat, 395 feet to the opposite field.
— Lance Brozdowski (@LanceBroz) November 2, 2021
Brett Taylor contributed to this post.